Baby Bolas & Ugin

Flying, Myriad & Evolve (When a creature enters the battlefield under your control, if
it has greater power or toughness than this creature, put a +1/+1 counter on this creature)

At the beginning of your upkeep if this has 5
or more +1/+1 counters on it, then it Fights
itself. (It will deal damage to itself rather
than to a creature that you target)