Casey Jr is a small young tender engine who used to be a full-time circus engine from Florida before coming to Transportonia and joining the Peterson Fleet.

Casey Jr is well known by any and all Transporonians as a bit of a prankster and can be just as cheeky as his friend Thomas Being an engine with plenty of experience on the rails, Casey Jr maintains a laid-back attitude with his fellow engines, though he can be rather uncomfortable every now and then, like going up and down steep hills like Highlee Hill in case he either gets stuck going up, or derails at the bottom. He's a good friend to many of Transportonia's residents, but isn't afraid of telling someone else that either insults him or hurts any of his friends. Pretty much the best you can describe him is that he's helpful, cheeky, and always looking out for a friend in need.

His voice source is freelanced, meaning so long as it’s within the age range, anything goes.