Constrictor Sage [Tarkir: Dragonstorm]

When this creature enters, tap target creature an opponent controls and put a stun counter on it. (If a permanent with a stun counter would become untapped, remove one from it instead.)
Renew — 2U, Exile this card from your graveyard: Tap target creature an opponent controls and put a stun counter on it. Activate only as a sorcery.