Living Birthing Chamber

Graft X (This creature enters the battlefield with X +1/+1 counters on it. Whenever another creature enters the battlefield, if this permanent has a +1/+1 counter on it, you may move a +1/+1 counter from this permanent onto that creature.)
Creatures you control with a +1/+1 counter on them have Evolve. (Whenever a creature enters the battlefield under your control, if that creature has greater power or toughness than this creature, put a +1/+1 counter on this creature.)