Lurking Evil

Pay half your life, rounded up: Lurking Evil becomes a 4/4 Phyrexian Horror creature with flying.

Phyrexian Totem

{T}: Add {B}.
{2}{B}: Phyrexian Totem becomes a 5/5 black Phyrexian Horror artifact creature with trample until end of turn.
Whenever Phyrexian Totem is dealt damage, if it's a creature, sacrifice that many permanents.

Genju of the Cedars

Enchant Forest
{2}: Enchanted Forest becomes a 4/4 green Spirit creature until end of turn. It's still a land.
When enchanted Forest is put into a graveyard, you may return Genju of the Cedars from your graveyard to your hand.

Opal Champion

When an opponent casts a creature spell, if Opal Champion is an enchantment, Opal Champion becomes a 3/3 Knight creature with first strike.

Orzhov Keyrune

{T}: Add {W} or {B}.
{W}{B}: Orzhov Keyrune becomes a 1/4 white and black Thrull artifact creature with lifelink until end of turn.

Genju of the Realm

Enchant land
{2}: Enchanted land becomes a legendary 8/12 Spirit creature with trample until end of turn. It's still a land.
When enchanted land is put into a graveyard, you may return Genju of the Realm from your graveyard to your hand.

Raging Ravine

Raging Ravine enters tapped.
{T}: Add {R} or {G}.
{2}{R}{G}: Until end of turn, Raging Ravine becomes a 3/3 red and green Elemental creature with "Whenever this creature attacks, put a +1/+1 counter on it." It's still a land.

Slumbering Tora

{2}, Discard a Spirit or Arcane card: Slumbering Tora becomes an X/X Cat artifact creature until end of turn, where X is the discarded card's mana value.

Rageform

When Rageform enters, it becomes an Aura with enchant creature. Manifest the top card of your library and attach Rageform to it. (To manifest a card, put it onto the battlefield face down as a 2/2 creature. Turn it face up any time for its mana cost if it's a creature card.)
Enchanted creature has double strike. (It deals both first-strike and regular combat damage.)

Shambling Vent

Shambling Vent enters tapped.
{T}: Add {W} or {B}.
{1}{W}{B}: Shambling Vent becomes a 2/3 white and black Elemental creature with lifelink until end of turn. It's still a land.

Lavaclaw Reaches

Lavaclaw Reaches enters tapped.
{T}: Add {B} or {R}.
{1}{B}{R}: Until end of turn, Lavaclaw Reaches becomes a 2/2 black and red Elemental creature with "{X}: This creature gets +X/+0 until end of turn." It's still a land.

Guardian Idol

Guardian Idol enters tapped.
{T}: Add {C}.
{2}: Guardian Idol becomes a 2/2 Golem artifact creature until end of turn.

Hidden Predators

When an opponent controls a creature with power 4 or greater, if Hidden Predators is an enchantment, Hidden Predators becomes a 4/4 Beast creature.

Opal Titan

When an opponent casts a creature spell, if Opal Titan is an enchantment, Opal Titan becomes a 4/4 Giant creature with protection from each of that spell's colors.

Hidden Guerrillas

When an opponent casts an artifact spell, if Hidden Guerrillas is an enchantment, Hidden Guerrillas becomes a 5/3 Soldier creature with trample.

Den of the Bugbear

If you control two or more other lands, Den of the Bugbear enters tapped.
{T}: Add {R}.
{3}{R}: Until end of turn, Den of the Bugbear becomes a 3/2 red Goblin creature with "Whenever this creature attacks, create a 1/1 red Goblin creature token that's tapped and attacking." It's still a land.

Ghitu Encampment

Ghitu Encampment enters tapped.
{T}: Add {R}.
{1}{R}: Ghitu Encampment becomes a 2/1 red Warrior creature with first strike until end of turn. It's still a land. (It deals combat damage before creatures without first strike.)

Hidden Gibbons

When an opponent casts an instant spell, if Hidden Gibbons is an enchantment, Hidden Gibbons becomes a 4/4 Ape creature.

Genju of the Spires

Enchant Mountain
{2}: Enchanted Mountain becomes a 6/1 red Spirit creature until end of turn. It's still a land.
When enchanted Mountain is put into a graveyard, you may return Genju of the Spires from your graveyard to your hand.

Mirage Mirror

{2}: Mirage Mirror becomes a copy of target artifact, creature, enchantment, or land until end of turn.

Glint Hawk Idol

Whenever another artifact you control enters, you may have Glint Hawk Idol become a 2/2 Bird artifact creature with flying until end of turn.
{W}: Glint Hawk Idol becomes a 2/2 Bird artifact creature with flying until end of turn.

Wandering Fumarole

Wandering Fumarole enters tapped.
{T}: Add {U} or {R}.
{2}{U}{R}: Until end of turn, Wandering Fumarole becomes a 1/4 blue and red Elemental creature with "{0}: Switch this creature's power and toughness until end of turn." It's still a land.

Veiled Apparition

When an opponent casts a spell, if Veiled Apparition is an enchantment, Veiled Apparition becomes a 3/3 Illusion creature with flying and "At the beginning of your upkeep, sacrifice Veiled Apparition unless you pay {1}{U}."

Veiled Sentry

When an opponent casts a spell, if Veiled Sentry is an enchantment, Veiled Sentry becomes an Illusion creature with power and toughness each equal to that spell's mana value.

Nantuko Monastery

{T}: Add {C}.
Threshold — {G}{W}: Nantuko Monastery becomes a 4/4 green and white Insect Monk creature with first strike until end of turn. It's still a land. Activate only if seven or more cards are in your graveyard.

Thunder Totem

{T}: Add {W}.
{1}{W}{W}: Thunder Totem becomes a 2/2 white Spirit artifact creature with flying and first strike until end of turn.

Treetop Village

Treetop Village enters tapped.
{T}: Add {G}.
{1}{G}: Treetop Village becomes a 3/3 green Ape creature with trample until end of turn. It's still a land. (It can deal excess combat damage to the player or planeswalker it's attacking.)

Weatherseed Totem

{T}: Add {G}.
{2}{G}{G}{G}: Weatherseed Totem becomes a 5/3 green Treefolk artifact creature with trample until end of turn.
When Weatherseed Totem is put into a graveyard from the battlefield, if it was a creature, return this card to its owner's hand.

Stirring Wildwood

Stirring Wildwood enters tapped.
{T}: Add {G} or {W}.
{1}{G}{W}: Until end of turn, Stirring Wildwood becomes a 3/4 green and white Elemental creature with reach. It's still a land.

Chimeric Sphere

{2}: Until end of turn, Chimeric Sphere becomes a 2/1 Construct artifact creature with flying.
{2}: Until end of turn, Chimeric Sphere becomes a 3/2 Construct artifact creature and loses flying.

Veiled Serpent

When an opponent casts a spell, if Veiled Serpent is an enchantment, Veiled Serpent becomes a 4/4 Serpent creature with "This creature can't attack unless defending player controls an Island."
Cycling {2} ({2}, Discard this card: Draw a card.)

Creeping Tar Pit

Creeping Tar Pit enters tapped.
{T}: Add {U} or {B}.
{1}{U}{B}: Creeping Tar Pit becomes a 3/2 blue and black Elemental creature until end of turn and can't be blocked this turn. It's still a land.

Mimic

{T}, Sacrifice Mimic: Add one mana of any color.
{2}: Mimic becomes a Shapeshifter artifact creature with base power and toughness 3/3 until end of turn.

Chronatog Totem

{T}: Add {U}.
{1}{U}: Chronatog Totem becomes a 1/2 blue Atog artifact creature until end of turn.
{0}: Chronatog Totem gets +3/+3 until end of turn. You skip your next turn. Activate only once each turn and only if Chronatog Totem is a creature.

Answered Prayers

Whenever a creature you control enters, you gain 1 life. If Answered Prayers isn't a creature, it becomes a 3/3 Angel creature with flying in addition to its other types until end of turn.

Chimeric Staff

{X}: Chimeric Staff becomes an X/X Construct artifact creature until end of turn.

Cloudform

When Cloudform enters, it becomes an Aura with enchant creature. Manifest the top card of your library and attach Cloudform to it. (To manifest a card, put it onto the battlefield face down as a 2/2 creature. Turn it face up any time for its mana cost if it's a creature card.)
Enchanted creature has flying and hexproof.

Shapeshifter's Marrow

At the beginning of each opponent's upkeep, that player reveals the top card of their library. If it's a creature card, the player puts the card into their graveyard and Shapeshifter's Marrow becomes a copy of that card. (If it does, it loses this ability.)

Levitating Statue

Flying
Whenever you cast a noncreature spell, put a +1/+1 counter on Levitating Statue.
{2}: Levitating Statue becomes a 1/1 Construct artifact creature until end of turn.

Hissing Quagmire

Hissing Quagmire enters tapped.
{T}: Add {B} or {G}.
{1}{B}{G}: Hissing Quagmire becomes a 2/2 black and green Elemental creature with deathtouch until end of turn. It's still a land.

Jade Idol

Whenever you cast a Spirit or Arcane spell, Jade Idol becomes a 4/4 Spirit artifact creature until end of turn.

Restless Cottage

Restless Cottage enters tapped.
{T}: Add {B} or {G}.
{2}{B}{G}: Restless Cottage becomes a 4/4 black and green Horror creature until end of turn. It's still a land.
Whenever Restless Cottage attacks, create a Food token and exile up to one target card from a graveyard.

Hive of the Eye Tyrant

If you control two or more other lands, Hive of the Eye Tyrant enters tapped.
{T}: Add {B}.
{3}{B}: Until end of turn, Hive of the Eye Tyrant becomes a 3/3 black Beholder creature with menace and "Whenever this creature attacks, exile target card from defending player's graveyard." It's still a land.

Still Life

{G}{G}: Still Life becomes a 4/3 Centaur creature in addition to its other types until end of turn.

Opal Caryatid

When an opponent casts a creature spell, if Opal Caryatid is an enchantment, Opal Caryatid becomes a 2/2 Soldier creature.

Stalking Stones

{T}: Add {C}.
{6}: Stalking Stones becomes a 3/3 Elemental artifact creature that's still a land. (This effect lasts indefinitely.)

The Blackstaff of Waterdeep

You may choose not to untap The Blackstaff of Waterdeep during your untap step.
Animate Walking Statue — {1}{U}, {T}: Another target nontoken artifact you control becomes a 4/4 artifact creature for as long as The Blackstaff of Waterdeep remains tapped. Activate only as a sorcery.

Chimeric Egg

Whenever an opponent casts a nonartifact spell, put a charge counter on Chimeric Egg.
Remove three charge counters from Chimeric Egg: Chimeric Egg becomes a 6/6 Construct artifact creature with trample until end of turn.

Chimeric Mass

Chimeric Mass enters with X charge counters on it.
{1}: Until end of turn, Chimeric Mass becomes a Construct artifact creature with "This creature's power and toughness are each equal to the number of charge counters on it."

Gruul Keyrune

{T}: Add {R} or {G}.
{R}{G}: Gruul Keyrune becomes a 3/2 red and green Beast artifact creature with trample until end of turn.

Dread Statuary

{T}: Add {C}.
{4}: Dread Statuary becomes a 4/2 Golem artifact creature until end of turn. It's still a land.

Opal Gargoyle

When an opponent casts a creature spell, if Opal Gargoyle is an enchantment, Opal Gargoyle becomes a 2/2 Gargoyle creature with flying.

Lurking Jackals

When an opponent has 10 or less life, if Lurking Jackals is an enchantment, it becomes a 3/2 Jackal creature.

Hidden Herd

When an opponent plays a nonbasic land, if Hidden Herd is an enchantment, Hidden Herd becomes a 3/3 Beast creature.

Cave of the Frost Dragon

If you control two or more other lands, Cave of the Frost Dragon enters tapped.
{T}: Add {W}.
{4}{W}: Cave of the Frost Dragon becomes a 3/4 white Dragon creature with flying until end of turn. It's still a land.

Genju of the Falls

Enchant Island
{2}: Enchanted Island becomes a 3/2 blue Spirit creature with flying until end of turn. It's still a land.
When enchanted Island is put into a graveyard, you may return Genju of the Falls from your graveyard to your hand.

Azorius Keyrune

{T}: Add {W} or {U}.
{W}{U}: Azorius Keyrune becomes a 2/2 white and blue Bird artifact creature with flying until end of turn.

Simic Keyrune

{T}: Add {G} or {U}.
{G}{U}: Simic Keyrune becomes a 2/3 green and blue Crab artifact creature with hexproof until end of turn. (It can't be the target of spells or abilities your opponents control.)

Restless Spire

Restless Spire enters tapped.
{T}: Add {U} or {R}.
{U}{R}: Until end of turn, Restless Spire becomes a 2/1 blue and red Elemental creature with "During your turn, this creature has first strike." It's still a land.
Whenever Restless Spire attacks, scry 1.

Hidden Stag

Whenever an opponent plays a land, if Hidden Stag is an enchantment, Hidden Stag becomes a 3/2 Elk Beast creature.
Whenever you play a land, if Hidden Stag is a creature, Hidden Stag becomes an enchantment.

Haunted Plate Mail

Equipped creature gets +4/+4.
{0}: Until end of turn, Haunted Plate Mail becomes a 4/4 Spirit artifact creature that's no longer an Equipment. Activate only if you control no creatures.
Equip {4} ({4}: Attach to target creature you control. Equip only as a sorcery.)

Mobilized District

{T}: Add {C}.
{4}: Mobilized District becomes a 3/3 Citizen creature with vigilance until end of turn. It's still a land. This ability costs {1} less to activate for each legendary creature and planeswalker you control.

Mishra's Factory

{T}: Add {C}.
{1}: Mishra's Factory becomes a 2/2 Assembly-Worker artifact creature until end of turn. It's still a land.
{T}: Target Assembly-Worker creature gets +1/+1 until end of turn.

Dromoka Monument

{T}: Add {G} or {W}.
{4}{G}{W}: Dromoka Monument becomes a 4/4 green and white Dragon artifact creature with flying until end of turn.

Atarka Monument

{T}: Add {R} or {G}.
{4}{R}{G}: Atarka Monument becomes a 4/4 red and green Dragon artifact creature with flying until end of turn.

Veiled Crocodile

When a player has no cards in hand, if Veiled Crocodile is an enchantment, Veiled Crocodile becomes a 4/4 Crocodile creature.

Opal Acrolith

Whenever an opponent casts a creature spell, if Opal Acrolith is an enchantment, Opal Acrolith becomes a 2/4 Soldier creature.
{0}: Opal Acrolith becomes an enchantment.

Mizzium Transreliquat

{3}: Mizzium Transreliquat becomes a copy of target artifact until end of turn.
{1}{U}{R}: Mizzium Transreliquat becomes a copy of target artifact, except it has this ability.

Hall of Storm Giants

If you control two or more other lands, Hall of Storm Giants enters tapped.
{T}: Add {U}.
{5}{U}: Until end of turn, Hall of Storm Giants becomes a 7/7 blue Giant creature with ward {3}. It's still a land. (Whenever it becomes the target of a spell or ability an opponent controls, counter it unless that player pays {3}.)

Opal Archangel

When an opponent casts a creature spell, if Opal Archangel is an enchantment, Opal Archangel becomes a 5/5 Angel creature with flying and vigilance.

Darksteel Brute

Indestructible (Damage and effects that say "destroy" don't destroy this artifact.)
{3}: Darksteel Brute becomes a 2/2 Beast artifact creature until end of turn.

Testament of Faith

{X}: Testament of Faith becomes an X/X Wall creature with defender in addition to its other types until end of turn.

Boros Keyrune

{T}: Add {R} or {W}.
{R}{W}: Boros Keyrune becomes a 1/1 red and white Soldier artifact creature with double strike until end of turn. (It deals both first-strike and regular combat damage.)

Veil of Birds

When an opponent casts a spell, if Veil of Birds is an enchantment, Veil of Birds becomes a 1/1 Bird creature with flying.

Dire Mimic

Flash
{T}, Sacrifice Dire Mimic: Add one mana of any color.
{3}: Dire Mimic becomes a Shapeshifter artifact creature with base power and toughness 5/5 until end of turn.

Dimir Keyrune

{T}: Add {U} or {B}.
{U}{B}: Dimir Keyrune becomes a 2/2 blue and black Horror artifact creature until end of turn and can't be blocked this turn.

Chimeric Coils

{X}{1}: Chimeric Coils becomes an X/X Construct artifact creature. Sacrifice it at the beginning of the next end step.

Spawning Pool

Spawning Pool enters tapped.
{T}: Add {B}.
{1}{B}: Spawning Pool becomes a 1/1 black Skeleton creature with "{B}: Regenerate this creature" until end of turn. It's still a land. (If it regenerates, the next time it would be destroyed this turn, it isn't. Instead tap it, remove all damage from it, and remove it from combat.)

Selesnya Keyrune

{T}: Add {G} or {W}.
{G}{W}: Selesnya Keyrune becomes a 3/3 green and white Wolf artifact creature until end of turn.

Frostwalk Bastion

{T}: Add {C}.
{1}{S}: Until end of turn, Frostwalk Bastion becomes a 2/3 Construct artifact creature. It's still a land. ({S} can be paid with one mana from a snow source.)
Whenever Frostwalk Bastion deals combat damage to a creature, tap that creature and it doesn't untap during its controller's next untap step.

Forbidding Watchtower

Forbidding Watchtower enters tapped.
{T}: Add {W}.
{1}{W}: Forbidding Watchtower becomes a 1/5 white Soldier creature until end of turn. It's still a land.

Izzet Keyrune

{T}: Add {U} or {R}.
{U}{R}: Until end of turn, Izzet Keyrune becomes a 2/1 blue and red Elemental artifact creature.
Whenever Izzet Keyrune deals combat damage to a player, you may draw a card. If you do, discard a card.

Mishra's Foundry

{T}: Add {C}.
{2}: Mishra's Foundry becomes a 2/2 Assembly-Worker artifact creature until end of turn. It's still a land.
{1}, {T}: Target attacking Assembly-Worker gets +2/+2 until end of turn.

Kolaghan Monument

{T}: Add {B} or {R}.
{4}{B}{R}: Kolaghan Monument becomes a 4/4 black and red Dragon artifact creature with flying until end of turn.

Titania's Song

Each noncreature artifact loses all abilities and becomes an artifact creature with power and toughness each equal to its mana value. If Titania's Song leaves the battlefield, this effect continues until end of turn.

Celestial Colonnade

Celestial Colonnade enters tapped.
{T}: Add {W} or {U}.
{3}{W}{U}: Until end of turn, Celestial Colonnade becomes a 4/4 white and blue Elemental creature with flying and vigilance. It's still a land.

Xanthic Statue

{5}: Until end of turn, Xanthic Statue becomes an 8/8 Golem artifact creature with trample.

Ensouled Scimitar

{3}: Ensouled Scimitar becomes a 1/5 Spirit artifact creature with flying until end of turn. (Equipment that's a creature can't equip a creature.)
Equipped creature gets +1/+5.
Equip {2} ({2}: Attach to target creature you control. Equip only as a sorcery.)

Foriysian Totem

{T}: Add {R}.
{4}{R}: Foriysian Totem becomes a 4/4 red Giant artifact creature with trample until end of turn.
As long as Foriysian Totem is a creature, it can block an additional creature each combat.

Gruul War Plow

Creatures you control have trample.
{1}{R}{G}: Gruul War Plow becomes a 4/4 Juggernaut artifact creature until end of turn.

Fountain of Ichor

{T}: Add one mana of any color.
{3}: Fountain of Ichor becomes a 3/3 Dinosaur artifact creature until end of turn.

Myth Realized

Whenever you cast a noncreature spell, put a lore counter on Myth Realized.
{2}{W}: Put a lore counter on Myth Realized.
{W}: Until end of turn, Myth Realized becomes a Monk Avatar creature in addition to its other types and gains "This creature's power and toughness are each equal to the number of lore counters on it."

Restless Bivouac

Restless Bivouac enters tapped.
{T}: Add {R} or {W}.
{1}{R}{W}: Restless Bivouac becomes a 2/2 red and white Ox creature until end of turn. It's still a land.
Whenever Restless Bivouac attacks, put a +1/+1 counter on target creature you control.

Lightform

When Lightform enters, it becomes an Aura with enchant creature. Manifest the top card of your library and attach Lightform to it. (To manifest a card, put it onto the battlefield face down as a 2/2 creature. Turn it face up any time for its mana cost if it's a creature card.)
Enchanted creature has flying and lifelink.

Jade Statue

{2}: Jade Statue becomes a 3/6 Golem artifact creature until end of combat. Activate only during combat.

Hidden Spider

When an opponent casts a creature spell with flying, if Hidden Spider is an enchantment, Hidden Spider becomes a 3/5 Spider creature with reach. (It can block creatures with flying.)

Lumbering Falls

Lumbering Falls enters tapped.
{T}: Add {G} or {U}.
{2}{G}{U}: Lumbering Falls becomes a 3/3 green and blue Elemental creature with hexproof until end of turn. It's still a land.

Rakdos Keyrune

{T}: Add {B} or {R}.
{B}{R}: Rakdos Keyrune becomes a 3/1 black and red Devil artifact creature with first strike until end of turn.

Genju of the Fields

Enchant Plains
{2}: Until end of turn, enchanted Plains becomes a 2/5 white Spirit creature with "Whenever this creature deals damage, its controller gains that much life." It's still a land.
When enchanted Plains is put into a graveyard, you may return Genju of the Fields from your graveyard to your hand.

Genju of the Fens

Enchant Swamp
{2}: Until end of turn, enchanted Swamp becomes a 2/2 black Spirit creature with "{B}: This creature gets +1/+1 until end of turn." It's still a land.
When enchanted Swamp is put into a graveyard, you may return Genju of the Fens from your graveyard to your hand.

Opal Avenger

When you have 10 or less life, if Opal Avenger is an enchantment, Opal Avenger becomes a 3/5 Soldier creature.