It's used to express a very high level of anger towards someone, usually due to their actions. She'll have my guts for garters when she sees the vase I broke.
Pro Tip 2/3
Not literal
This phrase is an idiom and not meant to be taken literally; it's not about actual violence. He joked that the boss would have his guts for garters if he didn't meet the deadline.
Pro Tip 3/3
British origin
It's a British English idiom, so it's particularly understood and used by British speakers. Our coach said he'd have our guts for garters if we didn't practice harder.