Seven-Tail Mentor

When this creature enters or dies, put a +1/+1 counter on target creature or Vehicle you control.

Priest of Ancient Lore

When this creature enters, you gain 1 life and draw a card.

Plains

Cloudkin Seer

Flying
When this creature enters, draw a card.

Cloudshift

Exile target creature you control, then return that card to the battlefield under your control.

Displace

Exile up to two target creatures you control, then return those cards to the battlefield under their owner's control.

Thraben Inspector

When this creature enters, investigate. (Create a Clue token. It's an artifact with "{2}, Sacrifice this token: Draw a card.")

Tranquil Cove

This land enters tapped.
When this land enters, you gain 1 life.
{T}: Add {W} or {U}.

Network Disruptor

Flying
When this creature enters, tap target permanent.

Island

Candletrap

Enchant creature
Enchanted creature has defender.
Prevent all combat damage that would be dealt by enchanted creature.
Coven — {2}{W}, Sacrifice this Aura: Exile enchanted creature. Activate only if you control three or more creatures with different powers.

Mulldrifter

Flying
When this creature enters, draw two cards.
Evoke {2}{U} (You may cast this spell for its evoke cost. If you do, it's sacrificed when it enters.)

Man-o'-War

When this creature enters, return target creature to its owner's hand.

Momentary Blink

Exile target creature you control, then return it to the battlefield under its owner's control.
Flashback {3}{U} (You may cast this card from your graveyard for its flashback cost. Then exile it.)