A Drophyd, or Little Fishy Man is a fish that is in a heavy suit and kills people. They accept bribes and do blackmails.
The Drophyds work for tons:
Chairman Drek - He needed them so he could destroy the Grummels on their planet. They accepted the bribe- a large chunk of Raritanium, and fought from him. He then sold them as slaves once he had built the Obliterator.