Slithery Stalker

Slithery Stalker

Creature - Nightmare Horror | Power/Toughness: 1 / 1 (CMC 3)
Swampwalk (This creature can't be blocked as long as defending player controls a Swamp.)
When Slithery Stalker enters the battlefield, exile target green or white creature an opponent controls.
When Slithery Stalker leaves the battlefield, return the exiled card to the battlefield under its owner's control.