Hedron Crab

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

Elvish Mystic

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.

Rampaging Baloths

Trample
Landfall — Whenever a land you control enters, you may create a 4/4 green Beast creature token.

Llanowar Scout

{T}: You may put a land card from your hand onto the battlefield.

Frilled Mystic

Flash
When Frilled Mystic enters, you may counter target spell.

Tatyova, Benthic Druid

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

Mystic Snake

Flash
When Mystic Snake enters, counter target spell.

Seedborn Muse

Untap all permanents you control during each other player's untap step.

Archaeomancer

When Archaeomancer enters, return target instant or sorcery card from your graveyard to your hand.

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.

Grolnok, the Omnivore

Whenever a Frog you control attacks, mill three cards.
Whenever a permanent card is put into your graveyard from your library, exile it with a croak counter on it.
You may play lands and cast spells from among cards you own in exile with croak counters on them.

Birds of Paradise

Eternal Witness

When Eternal Witness enters, you may return target card from your graveyard to your hand.

Avenger of Zendikar

When Avenger of Zendikar enters, create a 0/1 green Plant creature token for each land you control.
Landfall — Whenever a land you control enters, you may put a +1/+1 counter on each Plant creature you control.