Case of the Locked Hothouse

You may play an additional land on each of your turns.
To solve — You control seven or more lands. (If unsolved, solve at the beginning of your end step.)
Solved — You may look at the top card of your library any time, and you may play lands and cast creature and enchantment spells from the top of your library.

Spore Frog

Sacrifice this creature: Prevent all combat damage that would be dealt this turn.

Search for Tomorrow

Search your library for a basic land card, put it onto the battlefield, then shuffle.
Suspend 2—{G} (Rather than cast this card from your hand, you may pay {G} and exile it with two time counters on it. At the beginning of your upkeep, remove a time counter. When the last is removed, you may cast it without paying its mana cost.)

Ranger Class

(Gain the next level as a sorcery to add its ability.)
When this Class enters, create a 2/2 green Wolf creature token.
{1}{G}: Level 2
Whenever you attack, put a +1/+1 counter on target attacking creature.
{3}{G}: Level 3
You may look at the top card of your library any time.
You may cast creature spells from the top of your library.

Fangs of Kalonia

Put a +1/+1 counter on target creature you control, then double the number of +1/+1 counters on each creature that had a +1/+1 counter put on it this way.
Overload {4}{G}{G} (You may cast this spell for its overload cost. If you do, change "target" in its text to "each.")

Tranquil Thicket

This land enters tapped.
{T}: Add {G}.
Cycling {G} ({G}, Discard this card: Draw a card.)

Prey Upon

Target creature you control fights target creature you don't control. (Each deals damage equal to its power to the other.)

Emerald Medallion

Green spells you cast cost {1} less to cast.

Dragon Blood

{3}, {T}: Put a +1/+1 counter on target creature.

Mowu, Loyal Companion

Vigilance, trample
If one or more +1/+1 counters would be put on Mowu, that many plus one +1/+1 counters are put on it instead.

Rope

Equipped creature gets +1/+2, has reach, and can't be blocked by more than one creature.
{2}, Sacrifice this Equipment: Draw a card.
Equip {3}

Iron Apprentice

This creature enters with a +1/+1 counter on it.
When this creature dies, if it had counters on it, put those counters on target creature you control.

Pollenbright Druid

When this creature enters, choose one —
• Put a +1/+1 counter on target creature.
• Proliferate. (Choose any number of permanents and/or players, then give each another counter of each kind already there.)

Stony Strength

Put a +1/+1 counter on target creature you control. Untap that creature.

Reclaim

Put target card from your graveyard on top of your library.

Hard-Hitting Question

Target creature you control deals damage equal to its power to target creature or planeswalker you don't control.

Sol Ring

Boar Umbra

Enchant creature
Enchanted creature gets +3/+3.
Umbra armor (If enchanted creature would be destroyed, instead remove all damage from it and destroy this Aura.)

Jiang Yanggu, Wildcrafter

Each creature you control with a +1/+1 counter on it has "{T}: Add one mana of any color."
−1: Put a +1/+1 counter on target creature.

Longstalk Brawl

Gift a tapped Fish (You may promise an opponent a gift as you cast this spell. If you do, they create a tapped 1/1 blue Fish creature token before its other effects.)
Choose target creature you control and target creature you don't control. Put a +1/+1 counter on the creature you control if the gift was promised. Then those creatures fight each other.

Unnatural Restoration

Return target permanent card from your graveyard to your hand. Proliferate. (Choose any number of permanents and/or players, then give each another counter of each kind already there.)

Prized Unicorn

All creatures able to block this creature do so.

Gift of Strength

Target creature gets +3/+3 and gains reach until end of turn.

Sunshower Druid

When this creature enters, put a +1/+1 counter on target creature and you gain 1 life.

Mind Stone

{T}: Add {C}.
{1}, {T}, Sacrifice this artifact: Draw a card.

Season of Growth

Whenever a creature you control enters, scry 1. (Look at the top card of your library. You may put that card on the bottom.)
Whenever you cast a spell that targets a creature you control, draw a card.

Forgotten Ancient

Whenever a player casts a spell, you may put a +1/+1 counter on this creature.
At the beginning of your upkeep, you may move any number of +1/+1 counters from this creature onto other creatures.

Serpent-Blade Assailant

Backup 1 (When this creature enters, put a +1/+1 counter on target creature. If that's another creature, it gains the following ability until end of turn.)
Deathtouch

Gift of the Viper

Put a +1/+1 counter, a reach counter, and a deathtouch counter on target creature. Untap it.

Caustic Caterpillar

{1}{G}, Sacrifice this creature: Destroy target artifact or enchantment.

Arcane Signet

{T}: Add one mana of any color in your commander's color identity.

Fireshrieker

Equipped creature has double strike. (It deals both first-strike and regular combat damage.)
Equip {2} ({2}: Attach to target creature you control. Equip only as a sorcery.)

Tranquility

Snake Umbra

Enchant creature
Enchanted creature gets +1/+1 and has "Whenever this creature deals damage to an opponent, you may draw a card."
Umbra armor (If enchanted creature would be destroyed, instead remove all damage from it and destroy this Aura.)

Ilysian Caryatid

{T}: Add one mana of any color. If you control a creature with power 4 or greater, add two mana of any one color instead.

Hardened Scales

If one or more +1/+1 counters would be put on a creature you control, that many plus one +1/+1 counters are put on it instead.

Peerless Recycling

Gift a card (You may promise an opponent a gift as you cast this spell. If you do, they draw a card before its other effects.)
Return target permanent card from your graveyard to your hand. If the gift was promised, instead return two target permanent cards from your graveyard to your hand.

Enchantress's Presence

Whenever you cast an enchantment spell, draw a card.

Vexing Bauble

Whenever a player casts a spell, if no mana was spent to cast it, counter that spell.
{1}, {T}, Sacrifice this artifact: Draw a card.

Sparring Construct

When this creature dies, put a +1/+1 counter on target creature you control.

Rampant Growth

Search your library for a basic land card, put that card onto the battlefield tapped, then shuffle.

Whisperer of the Wilds

{T}: Add {G}.
Ferocious — {T}: Add {G}{G}. Activate only if you control a creature with power 4 or greater.

Bone Saw

Equipped creature gets +1/+0.
Equip {1} ({1}: Attach to target creature you control. Equip only as a sorcery.)

Thirsting Roots

Choose one —
• Search your library for a basic land card, reveal it, put it into your hand, then shuffle.
• Proliferate. (Choose any number of permanents and/or players, then give each another counter of each kind already there.)

Return to Nature

Choose one —
• Destroy target artifact.
• Destroy target enchantment.
• Exile target card from a graveyard.

Beast Within

Destroy target permanent. Its controller creates a 3/3 green Beast creature token.

Forest

Reclamation Sage

When this creature enters, you may destroy target artifact or enchantment.

Short Bow

Equipped creature gets +1/+1 and has vigilance and reach.
Equip {1} ({1}: Attach to target creature you control. Equip only as a sorcery.)

Terrifying Presence

Prevent all combat damage that would be dealt by creatures other than target creature this turn.

Glint Weaver

Reach
When this creature enters, distribute three +1/+1 counters among one, two, or three target creatures, then you gain life equal to the greatest toughness among creatures you control.

Crushing Canopy

Choose one —
• Destroy target creature with flying.
• Destroy target enchantment.

Harmonize

Kami of Whispered Hopes

If one or more +1/+1 counters would be put on a permanent you control, that many plus one +1/+1 counters are put on that permanent instead.
{T}: Add X mana of any one color, where X is this creature's power.

Iron Bully

Menace (This creature can't be blocked except by two or more creatures.)
When this creature enters, put a +1/+1 counter on target creature.

Natural End

Destroy target artifact or enchantment. You gain 3 life.

Blackblade Reforged

Equipped creature gets +1/+1 for each land you control.
Equip legendary creature {3}
Equip {7}

Planewide Celebration

Choose four. You may choose the same mode more than once.
• Create a 2/2 Citizen creature token that's all colors.
• Return target permanent card from your graveyard to your hand.
• Proliferate.
• You gain 4 life.

Wasteland Viper

Deathtouch
Bloodrush — {G}, Discard this card: Target attacking creature gets +1/+2 and gains deathtouch until end of turn.

Cultivate

Search your library for up to two basic land cards, reveal those cards, put one onto the battlefield tapped and the other into your hand, then shuffle.

Rishkar, Peema Renegade

When Rishkar enters, put a +1/+1 counter on each of up to two target creatures.
Each creature you control with a counter on it has "{T}: Add {G}."

Courage in Crisis

Put a +1/+1 counter on target creature, then proliferate. (Choose any number of permanents and/or players, then give each another counter of each kind already there.)

Fanatical Strength

Target creature gets +3/+3 and gains trample until end of turn.

Court of Garenbrig

When this enchantment enters, you become the monarch.
At the beginning of your upkeep, distribute two +1/+1 counters among up to two target creatures. Then if you're the monarch, double the number of +1/+1 counters on each creature you control.

Evolution Sage

Landfall — Whenever a land you control enters, proliferate. (Choose any number of permanents and/or players, then give each another counter of each kind already there.)

Bond Beetle

When this creature enters, put a +1/+1 counter on target creature.

Smell Fear

Proliferate. (Choose any number of permanents and/or players, then give each another counter of each kind already there.)
Target creature you control fights up to one target creature you don't control.