Mossborn Hydra

Trample (This creature can deal excess combat damage to the player or planeswalker it's attacking.)
This creature enters with a +1/+1 counter on it.
Landfall — Whenever a land you control enters, double the number of +1/+1 counters on this creature.

Sazh's Chocobo

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

Forest

Zell Dincht

You may play an additional land on each of your turns.
Zell Dincht gets +1/+0 for each land you control.
At the beginning of your end step, return a land you control to its owner's hand.

Eumidian Terrabotanist

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

Bristly Bill, Spine Sower

Landfall — Whenever a land you control enters, put a +1/+1 counter on target creature.
{3}{G}{G}: Double the number of +1/+1 counters on each creature you control.

Sabotender

Reach
Landfall — Whenever a land you control enters, this creature deals 1 damage to each opponent.

Llanowar Elves

Fabled Passage

{T}, Sacrifice this land: 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.

Earthbender Ascension

When this enchantment enters, earthbend 2. Then search your library for a basic land card, put it onto the battlefield tapped, then shuffle.
Landfall — Whenever a land you control enters, put a quest counter on this enchantment. When you do, if it has four or more quest counters on it, put a +1/+1 counter on target creature you control. It gains trample until end of turn.

Icetill Explorer

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

Traveling Chocobo

You may look at the top card of your library any time.
You may play lands and cast Bird spells from the top of your library.
If a land or Bird you control entering the battlefield causes a triggered ability of a permanent you control to trigger, that ability triggers an additional time.