Hadrian, Predator's Steward

When Hadrian enters the battlefield and at the beginning of your upkeep, create X tapped 0/1
green Rabbit creature tokens with "exile this
creature at the beginning of your next end step"
where X is equal to the greatest power among creatures you control.
Whenever 3 or more creatures die under your control, put both a haste and a trample counter
onto target creature you control.