Oliver, The Sleepy

When Oliver, The Sleepy enters the battlefield
tap all creatures target player controls. They don't
untap. If Oliver, The Sleepy leaves the battlefield
exile all tapped permanents target player controls.
{4}{w/u}{w/u}: Return Oliver, The Sleepy from your graveyard, or exile, to the battlefield under your control.
Err... huh, you actually summoned a baby.
I didn't know you could do that...