Grevin, Cursed Warder

Protection from black and from white, deathsight
(Whenever a creature you control dies, scry 1.)
{b}, Pay 1 life: Create a 1/1 black Bird creature
token with flying.
Whenever Grevin attacks, you may sacrifice up
to three Birds you control. If you do, Grevin
gets +2/+2 and gains flying until end of turn.