Aha cool names!
I like the idea that the pirates are divided into separate races. Though the Metroid Prime 3 ones do have a semi-official name. I think the consensus around the fandom is that they're called Urtraghians(since Urtraghus is the name of the Prime 3 Pirate Homeworld in the Japanese version, and is referenced by the "Urtraghian Shriekbat" scan entry in the English version).
Oh god I have a pirate OC as well
->
fav.me/d64q1r5He is a tank-bred Urtraghian slave who was mortally injured and escaped to avoid execution. He was saved by a Luminoth who formed a sort of maternal sense of pity for him, and infused with their DNA, so he's a hybrid