Heh. Might have to roll him up. I'm thinking Forest Gnome (from his parents), allowing him to speak with the city's rats and cats. Urchin, obviously, as the Background. Maybe go Barbarian, though, for the abilities rather than the culture - for all his cheerful disposition, sometimes he. Just. Gets. Really. Mad. What do you reckon?
Not sure which studies you are referring to: Koko the Gorilla was given a stack photos containing pictures of humans and other primates she knew and asked to sort them. She put all the humans in one stack, and all of the other primates she knew in another. Curiously, she placed the photo of herself in the stack with the humans.
I was refering to experiments from the 60's, Project Washoe in which a family raised a Chimpanzee as a daughter in attempt to improve her language ability, and to the experiments of Dr. Lily which had a young woman living in a special flooded apartment with a dolphin. It had rather um controversial results.
I would go with a Wild Sorcerer who would always see the bright side of her wild surge mishaps. "I don't know about you four but I did not see that fireball at our feet coming? Saves me from having to put an extra pair of socks on my chilly toes. And I'm sure we'll all be thankful for the practice it gave us in case we meet a villainous fire mage. /Love it!