Where and when it shows up
Shifts 2โ5. It slams the side check-in window and disables your shutter.
The Head Banger is one of the few threats in the game where the "safe" option (giving it coffee) actually profits you sanity instead of just avoiding a loss. Letting it break the glass is a valid zero-cost alternative if you don't have coffee available โ the only actively wrong move is shooing it away empty-handed.