Grimgrin, Reconstructed

Grimgrin, Reconstructed enters the battlefield tapped and doesn't untap during your untap step.
Whenever another zombie creature enters the battlefield under your control, untap Grimgrin, Reconstructed and put a +1/+1 counter on it.
Remove X +1/+1 counters from Grimgrin, Reconstructed: Return target zombie creature card from your graveyard to the battlefield with converted mana X or less.