[TPS] Who drops these heads?

I’ve been looking and farming for the EMPR-TP and CMD0-TP heads for Clappy in The Pre-Sequel but I haven’t gotten those heads. People are saying the Bosun drops them as well as Zarpedon and the Sentinel. I want to know which boss, or bosses, drop these heads. I’ve mainly farmed the Sentinel and got lots of Moonstones, yay, but plenty of garbage purple-tier weapons.