Skithiryx, Rotting Tyrant

Flying, Haste, Infect
Creatures spells you cast with infect cost {4} less to
cast.
Whenever one or more creatures you control with
infect deal combat damage to a player, put a +1/+1
counter on each creature with infect you control.

Sacrifice Skithiryx: Creatures you control with
infect get +1/+1 and gain trample until end of turn
for each poison counter your opponents have.