RotRoot Hive

Devour x (As this enters the battlefield, you may sacrifice any number of creatures. This creature enters the battlefield with x number of +1/+1 counters on it.)
When Rotroot Hive enters the battlefield with three slumber counters on it (As long as it has a slumber counter on it, it isn't a creature.)
Whenever a player attacks you or a planeswalker you control, remove a slumber counter from Rotroot Hive.