Omnath, Locus of Mana

You don't lose unspent green mana as steps and phases end.
Omnath gets +1/+1 for each unspent green mana you have.

Rammas Echor, Ancient Shield

Whenever you cast your second spell each turn, draw a card, then create a 0/3 white Wall creature token with defender.
At the beginning of combat on your turn, creatures you control with defender gain exalted until end of turn. (Whenever a creature you control attacks alone, it gets +1/+1 until end of turn for each instance of exalted among permanents you control.)

Thallid Shell-Dweller

Defender
At the beginning of your upkeep, put a spore counter on this creature.
Remove three spore counters from this creature: Create a 1/1 green Saproling creature token.

Shield Sphere

Defender
Whenever this creature blocks, put a -0/-1 counter on it.

Bojuka Bog

This land enters tapped.
When this land enters, exile target player's graveyard.
{T}: Add {B}.

Nykthos, Shrine to Nyx

{T}: Add {C}.
{2}, {T}: Choose a color. Add an amount of mana of that color equal to your devotion to that color. (Your devotion to a color is the number of mana symbols of that color in the mana costs of permanents you control.)

The Wanderer

Prevent all noncombat damage that would be dealt to you and other permanents you control.
−2: Exile target creature with power 4 or greater.

Axebane Guardian

Defender
{T}: Add X mana in any combination of colors, where X is the number of creatures you control with defender.

Baldin, Century Herdmaster

During your turn, each creature assigns combat damage equal to its toughness rather than its power.
Whenever Baldin attacks, up to one hundred target creatures each get +0/+X until end of turn, where X is the number of cards in your hand.

Wall of Souls

Defender (This creature can't attack.)
Whenever this creature is dealt combat damage, it deals that much damage to target opponent or planeswalker.

Nethroi, Apex of Death

Mutate {4}{G/W}{B}{B} (If you cast this spell for its mutate cost, put it over or under target non-Human creature you own. They mutate into the creature on top plus all abilities from under it.)
Deathtouch, lifelink
Whenever this creature mutates, return any number of target creature cards with total power 10 or less from your graveyard to the battlefield.

Overgrown Battlement

Defender
{T}: Add {G} for each creature you control with defender.

Weathered Sentinels

Defender, vigilance, reach, trample
This creature can attack players who attacked you during their last turn as though it didn't have defender.
Whenever this creature attacks, it gets +3/+3 and gains indestructible until end of turn.

Command the Dreadhorde

Choose any number of target creature and/or planeswalker cards in graveyards. Command the Dreadhorde deals damage to you equal to the total mana value of those cards. Put them onto the battlefield under your control.

Doran, the Siege Tower

Each creature assigns combat damage equal to its toughness rather than its power.

Carven Caryatid

Defender (This creature can't attack.)
When this creature enters, draw a card.

Vault of the Archangel

{T}: Add {C}.
{2}{W}{B}, {T}: Creatures you control gain deathtouch and lifelink until end of turn.

Cabal Coffers

{2}, {T}: Add {B} for each Swamp you control.

Dragon's Eye Sentry

Urborg, Tomb of Yawgmoth

Each land is a Swamp in addition to its other land types.

Foriysian Interceptor

Flash (You may cast this spell any time you could cast an instant.)
Defender
This creature can block an additional creature each combat.

Wakestone Gargoyle

Defender, flying
{1}{W}: Creatures you control with defender can attack this turn as though they didn't have defender.

Tree of Redemption

Defender
{T}: Exchange your life total with this creature's toughness.

Pride Guardian

Defender
Whenever this creature blocks, you gain 3 life.

Scrubland

Felothar the Steadfast

Each creature you control assigns combat damage equal to its toughness rather than its power.
Creatures you control can attack as though they didn't have defender.
{3}, {T}, Sacrifice another creature: Draw cards equal to the sacrificed creature's toughness, then discard cards equal to its power.

Wall of Blossoms

Defender
When this creature enters, draw a card.

Wall of Junk

Defender (This creature can't attack.)
When this creature blocks, return it to its owner's hand at end of combat. (Return it only if it's on the battlefield.)

Wall of Tanglecord

Defender
{G}: This creature gains reach until end of turn. (It can block creatures with flying.)

Commander's Sphere

{T}: Add one mana of any color in your commander's color identity.
Sacrifice this artifact: Draw a card.

Archers' Parapet

Defender
{1}{B}, {T}: Each opponent loses 1 life.

Chromatic Orrery

You may spend mana as though it were mana of any color.
{T}: Add {C}{C}{C}{C}{C}.
{5}, {T}: Draw a card for each color among permanents you control.

Command Tower

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

Teyo, the Shieldmage

You have hexproof. (You can't be the target of spells or abilities your opponents control.)
−2: Create a 0/3 white Wall creature token with defender.

Demonic Tutor

Search your library for a card, put that card into your hand, then shuffle.

Towering Titan

This creature enters with X +1/+1 counters on it, where X is the total toughness of other creatures you control.
Sacrifice a creature with defender: All creatures gain trample until end of turn.

Suspicious Bookcase

Defender
{3}, {T}: Target creature can't be blocked this turn.

Reanimate

Put target creature card from a graveyard onto the battlefield under your control. You lose life equal to that card's mana value.

Deadly Rollick

If you control a commander, you may cast this spell without paying its mana cost.
Exile target creature.

Barrier of Bones

Defender
When this creature enters, surveil 1. (Look at the top card of your library. You may put that card into your graveyard.)

Black Oak of Odunos

Defender
{B}, Tap another untapped creature you control: This creature gets +1/+1 until end of turn.

Chromatic Lantern

Lands you control have "{T}: Add one mana of any color."
{T}: Add one mana of any color.

Rogue's Passage

{T}: Add {C}.
{4}, {T}: Target creature can't be blocked this turn.

Wall of Omens

Steel Wall

Moorland Rescuer

When this creature dies, return any number of other creature cards with total power X or less from your graveyard to the battlefield, where X is this creature's power. Exile this card.

Bayou

Aura Shards

Whenever a creature you control enters, you may destroy target artifact or enchantment.

Sidar Kondo of Jamuraa

Flanking (Whenever a creature without flanking blocks this creature, the blocking creature gets -1/-1 until end of turn.)
Creatures your opponents control without flying or reach can't block creatures with power 2 or less.
Partner (You can have two commanders if both have partner.)

Verdant Catacombs

{T}, Pay 1 life, Sacrifice this land: Search your library for a Swamp or Forest card, put it onto the battlefield, then shuffle.

Consulate Skygate

Defender
Reach (This creature can block creatures with flying.)

Jeskai Barricade

Flash (You may cast this spell any time you could cast an instant.)
Defender
When this creature enters, you may return another target creature you control to its owner's hand.

Excavated Wall

Defender
{1}, {T}: Mill a card. (Put the top card of your library into your graveyard.)

Gleaming Barrier

Defender
When this creature dies, create a Treasure token. (It's an artifact with "{T}, Sacrifice this token: Add one mana of any color.")

Windswept Heath

{T}, Pay 1 life, Sacrifice this land: Search your library for a Forest or Plains card, put it onto the battlefield, then shuffle.

Vampiric Tutor

Search your library for a card, then shuffle and put that card on top. You lose 2 life.

Crenellated Wall

Defender (This creature can't attack.)
{T}: Target creature gets +0/+4 until end of turn.

Living Wall

Defender (This creature can't attack.)
{1}: Regenerate this creature.

Plains

Opposition Agent

Flash
You control your opponents while they're searching their libraries.
While an opponent is searching their library, they exile each card they find. You may play those cards for as long as they remain exiled, and you may spend mana as though it were mana of any color to cast them.

Dazzling Ramparts

Defender
{1}{W}, {T}: Tap target creature.

Rise of the Dark Realms

Put all creature cards from all graveyards onto the battlefield under your control.

Crystal Barricade

Defender (This creature can't attack.)
You have hexproof. (You can't be the target of spells or abilities your opponents control.)
Prevent all noncombat damage that would be dealt to other creatures you control.

The Walls of Ba Sing Se

Defender
Other permanents you control have indestructible.

Tree of Perdition

Defender
{T}: Exchange target opponent's life total with this creature's toughness.

Perimeter Captain

Defender
Whenever a creature you control with defender blocks, you may gain 2 life.

Marsh Flats

{T}, Pay 1 life, Sacrifice this land: Search your library for a Plains or Swamp card, put it onto the battlefield, then shuffle.

Sporocyst

Ravenous (This creature enters with X +1/+1 counters on it. If X is 5 or more, draw a card when it enters.)
Defender
Spore Chimney — When this creature enters, search your library for up to X basic land cards, put them onto the battlefield tapped, then shuffle.

Jaddi Offshoot

Defender
Landfall — Whenever a land you control enters, you gain 1 life.

Urza's Saga

(As this Saga enters and after your draw step, add a lore counter. Sacrifice after III.)
I — This Saga gains "{T}: Add {C}."
II — This Saga gains "{2}, {T}: Create a 0/0 colorless Construct artifact creature token with 'This token gets +1/+1 for each artifact you control.'"
III — Search your library for an artifact card with mana cost {0} or {1}, put it onto the battlefield, then shuffle.

Wall of Wood

Angelic Wall

Defender (This creature can't attack.)
Flying

Marble Chalice

Stalwart Shield-Bearers

Defender
Other creatures you control with defender get +0/+2.

Imperial Seal

Worldly Tutor

Search your library for a creature card, reveal it, then shuffle and put the card on top.

Flumph

Defender, flying
Whenever this creature is dealt damage, you and target opponent each draw a card.

Savannah

Revealing Eye

Menace
When this creature transforms into Revealing Eye, target opponent reveals their hand. You may choose a nonland card from it. If you do, that player discards that card, then draws a card.

Concealing Curtains

Defender
{2}{B}: Transform this creature. Activate only as a sorcery.

Concealing Curtains // Revealing Eye

Wall of Limbs

Defender (This creature can't attack.)
Whenever you gain life, put a +1/+1 counter on this creature.
{5}{B}{B}, Sacrifice this creature: Target player loses X life, where X is this creature's power.

Arcane Signet

Forest

Eerie Ultimatum

Return any number of permanent cards with different names from your graveyard to the battlefield.

Sol Ring

Swamp

Guardians of Meletis

Tower Defense

Creatures you control get +0/+5 and gain reach until end of turn.

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.