Retreat to Valakut

Landfall — Whenever a land you control enters, choose one —
• Target creature gets +2/+0 until end of turn.
• Target creature can't block this turn.

Moraug, Fury of Akoum

Each creature you control gets +1/+0 for each time it has attacked this turn.
Landfall — Whenever a land you control enters, if it's your main phase, there's an additional combat phase after this phase. At the beginning of that combat, untap all creatures you control.

Akoum Hellkite

Flying
Landfall — Whenever a land you control enters, this creature deals 1 damage to any target. If that land is a Mountain, this creature deals 2 damage instead.

Roaring Earth

Landfall — Whenever a land you control enters, put a +1/+1 counter on target creature or Vehicle you control.
Channel — {X}{G}{G}, Discard this card: Put X +1/+1 counters on target land you control. It becomes a 0/0 green Spirit creature with haste. It's still a land.

Emergent Sequence

Search your library for a basic land card, put it onto the battlefield tapped, then shuffle. That land becomes a 0/0 green and blue Fractal creature that's still a land. Put a +1/+1 counter on it for each land you had enter the battlefield under your control this turn.

Prowling Felidar

Vigilance
Landfall — Whenever a land you control enters, put a +1/+1 counter on this creature.

Forest

Collective Voyage

Join forces — Starting with you, each player may pay any amount of mana. Each player searches their library for up to X basic land cards, where X is the total amount of mana paid this way, puts them onto the battlefield tapped, then shuffles.

Traverse the Ulvenwald

Search your library for a basic land card, reveal it, put it into your hand, then shuffle.
Delirium — If there are four or more card types among cards in your graveyard, instead search your library for a creature or land card, reveal it, put it into your hand, then shuffle.

Island

Fearless Fledgling

Landfall — Whenever a land you control enters, put a +1/+1 counter on this creature. It gains flying until end of turn.

Mysteries of the Deep

Draw two cards.
Landfall — If you had a land enter the battlefield under your control this turn, draw three cards instead.

Roil Elemental

Flying
Landfall — Whenever a land you control enters, you may gain control of target creature for as long as you control this creature.

Plated Geopede

First strike
Landfall — Whenever a land you control enters, this creature gets +2/+2 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.

District Guide

When this creature enters, you may search your library for a basic land card or Gate card, reveal it, put it into your hand, then shuffle.

Mountain

Akoum Hellhound

Landfall — Whenever a land you control enters, this creature gets +2/+2 until end of turn.

Retreat to Emeria

Landfall — Whenever a land you control enters, choose one —
• Create a 1/1 white Kor Ally creature token.
• Creatures you control get +1/+1 until end of turn.

Peregrine Drake

Flying
When this creature enters, untap up to five lands.

Emeria Angel

Flying
Landfall — Whenever a land you control enters, you may create a 1/1 white Bird creature token with flying.

Emeria Shepherd

Flying
Landfall — Whenever a land you control enters, you may return target nonland permanent card from your graveyard to your hand. If that land is a Plains, you may return that nonland permanent card to the battlefield instead.

Nissa, Resurgent Animist

Landfall — Whenever a land you control enters, add one mana of any color. Then if this is the second time this ability has resolved this turn, reveal cards from the top of your library until you reveal an Elf or Elemental card. Put that card into your hand and the rest on the bottom of your library in a random order.

Retreat to Coralhelm

Landfall — Whenever a land you control enters, choose one —
• You may tap or untap target creature.
• Scry 1. (Look at the top card of your library. You may put that card on the bottom.)

Valakut Exploration

Landfall — Whenever a land you control enters, exile the top card of your library. You may play that card for as long as it remains exiled.
At the beginning of your end step, if there are cards exiled with this enchantment, put them into their owner's graveyard, then this enchantment deals that much damage to each opponent.

Frontier Guide

{3}{G}, {T}: Search your library for a basic land card, put it onto the battlefield tapped, then shuffle.

Reshape the Earth

Search your library for up to ten land cards, put them onto the battlefield tapped, then shuffle.

Archaeomancer's Map

When this artifact enters, search your library for up to two basic Plains cards, reveal them, put them into your hand, then shuffle.
Whenever a land an opponent controls enters, if that player controls more lands than you, you may put a land card from your hand onto the battlefield.

Plains

Kodama's Reach

Lotus Cobra

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

Omnath, Locus of Creation

When Omnath enters, draw a card.
Landfall — Whenever a land you control enters, you gain 4 life if this is the first time this ability has resolved this turn. If it's the second time, add {R}{G}{W}{U}. If it's the third time, Omnath deals 4 damage to each opponent and each planeswalker you don't control.

Boreas Charger

Flying
When this creature leaves the battlefield, choose an opponent who controls more lands than you. Search your library for a number of Plains cards equal to the difference, reveal those cards, put one of them onto the battlefield tapped and the rest into your hand, then shuffle.

Tideforce Elemental

{U}, {T}: You may tap or untap another target creature.
Landfall — Whenever a land you control enters, you may untap this creature.

Akoum Firebird

Flying, haste
This creature attacks each combat if able.
Landfall — Whenever a land you control enters, you may pay {4}{R}{R}. If you do, return this card from your graveyard to the battlefield.

Traverse Eternity

Draw cards equal to the greatest mana value among historic permanents you control. (Artifacts, legendaries, and Sagas are historic.)

Traverse the Outlands

Search your library for up to X basic land cards, where X is the greatest power among creatures you control. Put those cards onto the battlefield tapped, then shuffle.

Calcite Snapper

Shroud (This creature can't be the target of spells or abilities.)
Landfall — Whenever a land you control enters, you may switch this creature's power and toughness until end of turn.

Peregrination

Search your library for up to two basic land cards, reveal those cards, and put one onto the battlefield tapped and the other into your hand. Shuffle, then scry 1. (Look at the top card of your library. You may put that card on the bottom.)

Scute Mob

At the beginning of your upkeep, if you control five or more lands, put four +1/+1 counters on this creature.

Ulvenwald Hydra

Reach
Ulvenwald Hydra's power and toughness are each equal to the number of lands you control.
When this creature enters, you may search your library for a land card, put it onto the battlefield tapped, then shuffle.