Nightmare

Stuff. (Hexproof, Flying. Whenever this is dealt damage, this gets +1/+1. When this enters the battlefield, This gets +1/+1.
When your turn ends, This gets 7 +1/+1 counters.
When your turn starts, This looses 7 +1/+1 counters. When this dies, create X -X/-X Nightmare Tokens
with Stuff. X equals how many +1/+1 counters where on this. -X is how many times
this has died plus -1.)