Murderer of Crows

Menace, Spooky (this creature can only be blocked
by creatures with courage or spooky)
When Murderer of Crows enters the battlefield,
create three black 1/1 Crow creature tokens with flying.
Sacrifice a crow: Put a +1/+1 counter on
Murderer of Crows. It gains flying or indestructible until end of turn