When Ovinomancer enters the battlefield, sacrifice it unless you return three basic lands you control to their owner's hand.
, Return Ovinomancer to its owner's hand: Destroy target creature. It can't be regenerated. That creature's controller creates a 0/1 green Sheep creature token.
10/4/2004 Can target itself. This will cause it to be returned to your hand during announcement and will result in no sheep since it will not be on the battlefield at resolution so the effect fails since it target is illegal.