[@Lugia] What Zav says is true, while I'm giving you the option to choose it's suppose to be "random". If you meant something that would fit Trevor's personality I'd actually say Bug. Sort of weird, not really immediately useful, but at the same time surprisingly powerful when you least expect it. Mechanically speaking, Bug type is useful against Dark and Psychic, and based on your backstory Trevor did somehow manage to go ape on some bullies (Typically dark types) and is actually smart enough to go college (smart people stuff aka Psychic). Just as well right now Trevor might seem like he's kind of out of it, but when the going gets tough or they face off against a read bad guy, he'll have the chops to do some serious damage.