"Go batshit" is an informal and colloquial term that means to become extremely angry, agitated, or irrational. There are several synonyms for this phrase, such as go berserk, go nuts, go insane, go mad, lose one's mind, flip out, blow a fuse or go ballistic. These terms all convey the idea of becoming unhinged or losing control in a sudden and intense way. These phrases are often used in casual conversation to describe a person's sudden outburst or emotional meltdown. Using these synonyms can help to convey the intensity of someone's reaction or behavior in a more colorful and expressive way.