Counterspell

Island

Ravenous Chupacabra

When this creature enters, destroy target creature an opponent controls.

Baleful Strix

Flying, deathtouch
When this creature enters, draw a card.

Eaten Alive

As an additional cost to cast this spell, sacrifice a creature or pay {3}{B}.
Exile target creature or planeswalker.

Breathe Your Last

Destroy target creature or planeswalker. You gain 1 life for each of its colors.

Unsummon

Return target creature to its owner's hand.

Duress

Target opponent reveals their hand. You choose a noncreature, nonland card from it. That player discards that card.

Dimir Aqueduct

This land enters tapped.
When this land enters, return a land you control to its owner's hand.
{T}: Add {U}{B}.

Abyssal Harvester

{T}: Exile target creature card from a graveyard that was put there this turn. Create a token that's a copy of it, except it's a Nightmare in addition to its other types. Then exile all other Nightmare tokens you control.

Cauldron Familiar

When this creature enters, each opponent loses 1 life and you gain 1 life.
Sacrifice a Food: Return this card from your graveyard to the battlefield.

Agent of Treachery

When this creature enters, gain control of target permanent.
At the beginning of your end step, if you control three or more permanents you don't own, draw three cards.

Swamp

Watery Grave

({T}: Add {U} or {B}.)
As this land enters, you may pay 2 life. If you don't, it enters tapped.

Witch's Oven

{T}, Sacrifice a creature: Create a Food token. If the sacrificed creature's toughness was 4 or greater, create two Food tokens instead. (They're artifacts with "{2}, {T}, Sacrifice this token: You gain 3 life.")