Ruin Crab

Landfall — Whenever a land you control enters, each opponent mills three cards. (To mill a card, a player puts the top card of their library into their graveyard.)

Deadeye Navigator

Soulbond (You may pair this creature with another unpaired creature when either enters. They remain paired for as long as you control both of them.)
As long as Deadeye Navigator is paired with another creature, each of those creatures has "{1}{U}: Exile this creature, then return it to the battlefield under your control."

Yavimaya Coast

{T}: Add {C}.
{T}: Add {G} or {U}. Yavimaya Coast deals 1 damage to you.

Misty Rainforest

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

Waterlogged Grove

{T}, Pay 1 life: Add {G} or {U}.
{1}, {T}, Sacrifice Waterlogged Grove: Draw a card.

Constant Mists

Buyback—Sacrifice a land. (You may sacrifice a land in addition to any other costs as you cast this spell. If you do, put this card into your hand as it resolves.)
Prevent all combat damage that would be dealt this turn.

Temur Sabertooth

{1}{G}: You may return another creature you control to its owner's hand. If you do, Temur Sabertooth gains indestructible until end of turn.

Tatyova, Benthic Druid

Landfall — Whenever a land you control enters, you gain 1 life and draw a card.

Kodama of the East Tree

Reach
Whenever another permanent you control enters, if it wasn't put onto the battlefield with this ability, you may put a permanent card with equal or lesser mana value from your hand onto the battlefield.
Partner (You can have two commanders if both have partner.)

Tireless Tracker

Landfall — Whenever a land you control enters, investigate. (Create a Clue token. It's an artifact with "{2}, Sacrifice this artifact: Draw a card.")
Whenever you sacrifice a Clue, put a +1/+1 counter on Tireless Tracker.

Command Tower

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

Hinterland Harbor

Hinterland Harbor enters tapped unless you control a Forest or an Island.
{T}: Add {G} or {U}.

Spark Double

You may have Spark Double enter as a copy of a creature or planeswalker you control, except it enters with an additional +1/+1 counter on it if it's a creature, it enters with an additional loyalty counter on it if it's a planeswalker, and it isn't legendary.

Dryad of the Ilysian Grove

You may play an additional land on each of your turns.
Lands you control are every basic land type in addition to their other types.

Rhystic Study

Whenever an opponent casts a spell, you may draw a card unless that player pays {1}.

Harrow

As an additional cost to cast this spell, sacrifice a land.
Search your library for up to two basic land cards, put them onto the battlefield, then shuffle.

Storm Cauldron

Each player may play an additional land during each of their turns.
Whenever a land is tapped for mana, return it to its owner's hand.

Exploration

You may play an additional land on each of your turns.

Sakashima of a Thousand Faces

You may have Sakashima of a Thousand Faces enter as a copy of another creature you control, except it has Sakashima of a Thousand Faces's other abilities.
The "legend rule" doesn't apply to permanents you control.
Partner (You can have two commanders if both have partner.)

Hedron Crab

Landfall — Whenever a land you control enters, target player mills three cards.

Agent of Treachery

When Agent of Treachery enters, gain control of target permanent.
At the beginning of your end step, if you control three or more permanents you don't own, draw three cards.

Oboro, Palace in the Clouds

{T}: Add {U}.
{1}: Return Oboro, Palace in the Clouds to its owner's hand.

Botanical Sanctum

Botanical Sanctum enters tapped unless you control two or fewer other lands.
{T}: Add {G} or {U}.

Alchemist's Refuge

{T}: Add {C}.
{G}{U}, {T}: You may cast spells this turn as though they had flash.

Tropical Island

Simic Growth Chamber

Simic Growth Chamber enters tapped.
When Simic Growth Chamber enters, return a land you control to its owner's hand.
{T}: Add {G}{U}.

Scute Swarm

Landfall — Whenever a land you control enters, create a 1/1 green Insect creature token. If you control six or more lands, create a token that's a copy of Scute Swarm instead.

Wayward Swordtooth

Ascend (If you control ten or more permanents, you get the city's blessing for the rest of the game.)
You may play an additional land on each of your turns.
Wayward Swordtooth can't attack or block unless you have the city's blessing.

Meloku the Clouded Mirror

Flying
{1}, Return a land you control to its owner's hand: Create a 1/1 blue Illusion creature token with flying.

Oracle of Mul Daya

You may play an additional land on each of your turns.
Play with the top card of your library revealed.
You may play lands from the top of your library.

Crop Rotation

As an additional cost to cast this spell, sacrifice a land.
Search your library for a land card, put that card onto the battlefield, then shuffle.

Breeding Pool

({T}: Add {G} or {U}.)
As Breeding Pool enters, you may pay 2 life. If you don't, it enters tapped.

Ramunap Excavator

Rejuvenating Springs

Rejuvenating Springs enters tapped unless you have two or more opponents.
{T}: Add {G} or {U}.

Sunscorched Desert

When Sunscorched Desert enters, it deals 1 damage to target player or planeswalker.
{T}: Add {C}.

Palinchron

Flying
When Palinchron enters, untap up to seven lands.
{2}{U}{U}: Return Palinchron to its owner's hand.

Springbloom Druid

When Springbloom Druid enters, you may sacrifice a land. If you do, search your library for up to two basic land cards, put them onto the battlefield tapped, then shuffle.

Oko, Thief of Crowns

+2: Create a Food token. (It's an artifact with "{2}, {T}, Sacrifice this artifact: You gain 3 life.")
+1: Target artifact or creature loses all abilities and becomes a green Elk creature with base power and toughness 3/3.
−5: Exchange control of target artifact or creature you control and target creature an opponent controls with power 3 or less.

Cloudstone Curio

Whenever a nonartifact permanent you control enters, you may return another permanent you control that shares a permanent type with it to its owner's hand.

Lotus Cobra

Landfall — Whenever a land you control enters, add one mana of any color.

Prismatic Vista

{T}, Pay 1 life, Sacrifice Prismatic Vista: Search your library for a basic land card, put it onto the battlefield, then shuffle.

Aesi, Tyrant of Gyre Strait

You may play an additional land on each of your turns.
Landfall — Whenever a land you control enters, you may draw a card.

Bramble Sovereign

Whenever another nontoken creature enters, you may pay {1}{G}. If you do, that creature's controller creates a token that's a copy of that creature.

Fabled Passage

{T}, Sacrifice Fabled Passage: Search your library for a basic land card, put it onto the battlefield tapped, then shuffle. Then if you control four or more lands, untap that land.

Expedition Map

{2}, {T}, Sacrifice Expedition Map: Search your library for a land card, reveal it, put it into your hand, then shuffle.

Trade Routes

{1}: Return target land you control to its owner's hand.
{1}, Discard a land card: Draw a card.

Field of the Dead

Field of the Dead enters tapped.
{T}: Add {C}.
Whenever Field of the Dead or another land you control enters, if you control seven or more lands with different names, create a 2/2 black Zombie creature token.

Ancient Greenwarden

Reach
You may play lands from your graveyard.
If a land entering causes a triggered ability of a permanent you control to trigger, that ability triggers an additional time.

Patron of the Moon

Moonfolk offering (You may cast this spell any time you could cast an instant by sacrificing a Moonfolk and paying the difference in mana costs between this and the sacrificed Moonfolk. Mana cost includes color.)
Flying
{1}: Put up to two land cards from your hand onto the battlefield tapped.

Sakashima the Impostor

You may have Sakashima the Impostor enter as a copy of any creature on the battlefield, except its name is Sakashima the Impostor, it's legendary in addition to its other types, and it has "{2}{U}{U}: Return this creature to its owner's hand at the beginning of the next end step."

Cyclonic Rift

Return target nonland permanent you don't control to its owner's hand.
Overload {6}{U} (You may cast this spell for its overload cost. If you do, change "target" in its text to "each.")