Slimeseller

At the end of each step, any one opponent may
have you and them each flip a coin. Each player
who's flip comes up heads creates a 1/1 green
ooze creature token with a spill counter on it.
At the beginning of your upkeep, you may have
an opponent gain control of a creature you
control with a spill counter on it. Then, if a
player controls eight or more creatures with spill
counters on them, each player sacrifices all
oozes they control and takes 2 damage for each
creature they sacrificed this way