batshit

Fecal matter produced by bats

Nonsense, horseshit; especially when said by or attributed to someone irrational.

Extreme irrationality or unreasonableness, insanity, craziness.

Extremely irrational or unreasonable, insane, crazy.

“Don't take any courses from that professor. She's completely batshit.”

Used as an intensifier, particularly for insane or synonyms.

“When we heard about it he went batshit nuts.”