I want to make Theraputic Smile something that'll suit him more, but I don't know what.

He's about 18, nicknamed Smile. A very gentle, trusting person, but rather shy. Is willing to be friends with almost anyone if they are friendly to him. Can't speak English very well; broken sentaces. He would never harm someone, preferring to run rather than fight. He's also a necrophile, and has a child's corpse for his best friend.

... HELP PLZ. What pet and species do you think would suit him?

Hmm... Perhaps a Darkmatter Kerubi?

The pose and the facial expression seems a little bit introverted and shy, but could also be gentle and trusting. Also looks like the type to run rather than fight. IMO

Either Experiment 76166 or Experiment 8625. They suit...I think. xD