Mycoloth

Devour 2 (As this enters the battlefield, you may sacrifice any number of creatures. This creature enters the battlefield with twice that many +1/+1 counters on it.)
At the beginning of your upkeep, create a 1/1 green Saproling creature token for each +1/+1 counter on Mycoloth.

Preyseizer Dragon

Flying
Devour 2 (As this enters the battlefield, you may sacrifice any number of creatures. This creature enters the battlefield with twice that many +1/+1 counters on it.)
Whenever Preyseizer Dragon attacks, it deals damage to any target equal to the number of +1/+1 counters on Preyseizer Dragon.

Voracious Dragon

Flying
Devour 1 (As this enters the battlefield, you may sacrifice any number of creatures. This creature enters the battlefield with that many +1/+1 counters on it.)
When Voracious Dragon enters the battlefield, it deals damage to any target equal to twice the number of Goblins it devoured.

Gorger Wurm

Devour 1 (As this enters the battlefield, you may sacrifice any number of creatures. This creature enters the battlefield with that many +1/+1 counters on it.)

Marrow Chomper

Devour 2 (As this enters the battlefield, you may sacrifice any number of creatures. This creature enters the battlefield with twice that many +1/+1 counters on it.)
When Marrow Chomper enters the battlefield, you gain 2 life for each creature it devoured.

Gluttonous Slime

Flash
Devour 1 (As this enters the battlefield, you may sacrifice any number of creatures. This creature enters the battlefield with that many +1/+1 counters on it.)

Hellkite Hatchling

Devour 1 (As this enters the battlefield, you may sacrifice any number of creatures. This creature enters the battlefield with that many +1/+1 counters on it.)
Hellkite Hatchling has flying and trample if it devoured a creature.

Voracious Dragon

Flying
Devour 1 (As this enters the battlefield, you may sacrifice any number of creatures. This creature enters the battlefield with that many +1/+1 counters on it.)
When Voracious Dragon enters the battlefield, it deals damage to any target equal to twice the number of Goblins it devoured.

Thunder-Thrash Elder

Devour 3 (As this enters the battlefield, you may sacrifice any number of creatures. This creature enters the battlefield with three times that many +1/+1 counters on it.)

Tar Fiend

Devour 2 (As this enters the battlefield, you may sacrifice any number of creatures. This creature enters the battlefield with twice that many +1/+1 counters on it.)
When Tar Fiend enters the battlefield, target player discards a card for each creature it devoured.

Skullmulcher

Devour 1 (As this enters the battlefield, you may sacrifice any number of creatures. This creature enters the battlefield with that many +1/+1 counters on it.)
When Skullmulcher enters the battlefield, draw a card for each creature it devoured.

Mycoloth

Devour 2 (As this enters the battlefield, you may sacrifice any number of creatures. This creature enters the battlefield with twice that many +1/+1 counters on it.)
At the beginning of your upkeep, create a 1/1 green Saproling creature token for each +1/+1 counter on Mycoloth.

Predator Dragon

Flying, haste
Devour 2 (As this enters the battlefield, you may sacrifice any number of creatures. This creature enters the battlefield with twice that many +1/+1 counters on it.)

Thorn-Thrash Viashino

Devour 2 (As this enters the battlefield, you may sacrifice any number of creatures. This creature enters the battlefield with twice that many +1/+1 counters on it.)
: Thorn-Thrash Viashino gains trample until end of turn.

Caldera Hellion

Devour 1 (As this enters the battlefield, you may sacrifice any number of creatures. This creature enters the battlefield with that many +1/+1 counters on it.)
When Caldera Hellion enters the battlefield, it deals 3 damage to each creature.