Restless Skin-Carvers

Flying, devour -1 (As this creature enters the battlefield, you may sacrifice any number of creatures. This creature enters the battlefield
with a -1/-1 counter on it for each creature sacrificed this way.)
When Restless Skin-Carvers attacks, target creature gets -1/-1 until end of turn for each
-1/-1 counter on Restless Skin-Carvers.
Restless Skin-Carvers can't block.