Riptide Entrancer [Onslaught]

Cost: 1 U U Whenever Riptide Entrancer deals combat damage to a player, you may sacrifice it. If you do, gain control of target creature that player controls. (This effect lasts indefinitely.)
Morph U U (You may cast this card face down as a 2/2 creature for 3. Turn it face up any time for its morph cost.)