"A key with a bird's head attached."
Crow Key (カラスのカギ karasu no kagi ) is an item in Resident Evil 7: Biohazard.
This key opens two doors. The first is in the Old House and leads to the 2nd floor. The second is back in the previous house and allows the player to claim the Grenade Launcher.
It's found in a small hut in the Old House that you must reach by raising a walkway from the water.