"Batshit crazy" is a colloquial expression used to describe people or situations that are completely insane and irrational. While this phrase is commonly used in everyday language, it can be offensive and may not be appropriate in some situations. There are several alternatives that can be used instead of "batshit crazy" such as "off the wall", "bonkers", "nuts", "wild", "mad", or "intense". Additionally, people can use more formal phrases like "unreasonable", "illogical", "irrational", "absurd", or even "insane". These synonyms can help articulate a strong reaction to a situation without using slang or potentially offending others.