Crowmother, the All-Seeing

Eminence — Whenever a Crow Messenger token
would die, it phases out instead. Whenever a Crow
Messenger enters the battlefield, all phased out
Crow Messenger tokens phase back in.

Opponents cannot target Crowmother if there is
another Bird on the battlefield.

{g}{u}{b}: Sacrifice a friendly Bird creature, then
create a Crow Messenger token with Flying.