madder than a box of cats

This is a commonly used phase when describing a "very angry" person or person acting in a "crazy manner".

For example My boss was madder than a box of cats when he didn't get his monthly report on time

or My mum was madder than a box of cats with my dad on Friday.

madder than a baptist in a brothel

Really angry, may incite a physical altercation.

(Girlfriend after boyfriend caught cheating)

Catching him kissing my best friend just made me madder than a baptist in a brothel!