The phrase "alien bounty" refers to a reward or payment offered for capturing or proving the existence of extraterrestrial beings (aliens). Full definition
The Brother From Another Planet (1984) Using «brother» in this context was relegated solely to the exploitation genre until John Sayles wrote and directed this movie about a mute alien being chased by alien bounty hunters. (blog.bullz-eye.com)
Peter Quill, who calls himself Star - Lord, was born on Earth but was abducted shortly after the death of his mother, and was swept up into a strange world of alien bounty hunters, thieves and scavengers. (polygon.com)
How is everyone's favourite alien bounty hunter faring in her new adventure? (the-arcade.ie)