Swamp

Devouring Swarm

Flying
Sacrifice a creature: This creature gets +1/+1 until end of turn.

Virus Beetle

When this creature enters, each opponent discards a card.

Wriggling Grub

When this creature dies, create two 1/1 black and green Worm creature tokens.

Go for the Throat

Eaten Alive

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

Morkrut Necropod

Menace (This creature can't be blocked except by two or more creatures.)
Whenever this creature attacks or blocks, sacrifice another creature or land.

Subtle Strike

Choose one or both —
• Target creature gets -1/-1 until end of turn.
• Put a +1/+1 counter on target creature.

Torment of Scarabs

Enchant player
At the beginning of enchanted player's upkeep, that player loses 3 life unless they sacrifice a nonland permanent of their choice or discard a card.

Fumulus, the Infestation

Flying, deathtouch
Whenever a player sacrifices a nontoken creature, create a 1/1 black Insect creature token with flying.
Whenever an Insect, Leech, Slug, or Worm you control attacks, defending player loses 1 life and you gain 1 life.

Endless Cockroaches

When this creature dies, return it to its owner's hand.

Nantuko Husk

Sacrifice a creature: This creature gets +2/+2 until end of turn.

Thriving Moor

This land enters tapped. As it enters, choose a color other than black.
{T}: Add {B} or one mana of the chosen color.

Heartstabber Mosquito

Kicker {2}{B} (You may pay an additional {2}{B} as you cast this spell.)
Flying
When this creature enters, if it was kicked, destroy target creature.