Jameson Thwark prides himself on being the physically strongest resident of Teras Terrace. This may or may not be strictly true; there are a few residents who may possibly be stronger because of their sheer size, but their strength has never been directly compared to his. In any case, he's certainly the strongest Terrace inhabitant of the same order of magnitude of size as a human. Something of a fitness fanatic, Jameson spends much of his time exercising, makes sure to eat healthy, and makes a living as a personal trainer.
Aside from physical fitness, Jameson's passion is flowers, both making elaborate flower arrangements and growing his own flowers in his garden and in a greenhouse he shares with a botanist working for Pretorius Technologies. (Jameson himself, while having no formal training in botany, is knowledgeable enough about growing flowers that he's occasionally helped out the company in its studies himself.)