Dovin, Undercity Fugitive

Hexproof, deathtouch.
When Dovin, Undercity Fugitive enters the battlefield, tap target creature an opponent controls. That creature does not untap during its controller's untap step for as long as you control Dovin, Undercity Fugitive.
{w}{u}: Exile Dovin, Undercity Fugitive. At the start of your next end step, return him to the battlefield under your control.