Erratic Mutation

Choose target creature. Reveal cards from the top of your library until you reveal a nonland card. That creature gets +X/-X until end of turn, where X is that card's mana value. Put all cards revealed this way on the bottom of your library in any order.

Arcane Flight

Enchant creature
Enchanted creature gets +1/+1 and has flying.

Merfolk Mesmerist

Merrow Witsniper

When Merrow Witsniper enters, target player mills a card.

Whiplash Trap

If an opponent had two or more creatures enter the battlefield under their control this turn, you may pay {U} rather than pay this spell's mana cost.
Return two target creatures to their owners' hands.

Frightful Delusion

Counter target spell unless its controller pays {1}. That player discards a card.

Cloudkin Seer

Flying
When Cloudkin Seer enters, draw a card.

Coral Trickster

Morph {U} (You may cast this card face down as a 2/2 creature for {3}. Turn it face up any time for its morph cost.)
When Coral Trickster is turned face up, you may tap or untap target permanent.

Arctic Merfolk

Kicker—Return a creature you control to its owner's hand. (You may return a creature you control to its owner's hand in addition to any other costs as you cast this spell.)
If Arctic Merfolk was kicked, it enters with a +1/+1 counter on it.

Cancel

Essence Scatter

Island

Awesome Presence

Enchant creature
Enchanted creature can't be blocked unless defending player pays {3} for each creature they control that's blocking it.