Haunted One

Commander creatures you own have
“Whenever this creature becomes tapped, it
and other creatures you control that share a creature type with it each get +2/+0 and gain undying until end of turn.” (When a creature
with undying dies, if it had no +1/+1 counters
on it, return it to the battlefield under its
owner’s control with a +1/+1 counter on it.)