Severus Snape [Severitus]

The door swung open almost instantly, revealing Professor Snape. He’d been so quick that Harry half-suspected he’d been waiting by the door, prepared to pounce. Snape was wearing the same high-necked black robes he always wore when school was in session that reminded Harry so much of a bat.

"You're late," he hissed, beady eyes darting between Harry and the Headmaster. Snape was glaring at Harry in particular, like he was a bug that Snape would dearly love to stamp out.