Throw in a lil backstory here that doesn't fit elsewhere:

Rad is the byproduct of several crosses of dna in a cesspool of laboratory dumping. He was later discovered by the lab and captured and tested. He learned speech and how to read from his time in the lab and passed the majority of the time reading books. After escaping his confines he went into a seclusion, hiding along remote beaches and in sewers but never venturing too far from civilization- often returning for more books or studies.

He would aspire to become an archaeologist or adventurer would it not be for his treatment by humans. Rad holds nothing but contempt for others and will often sink a few ships or wreck a few buildings for a little bit of misanthropic fun.