Sebastian used to be a cute little baby kougra:
But he got tired of being so much smaller than all of his siblings, so he became a big tough mutant. THEN he got tired of... okay, you know what? Forget the cutesy story. I got sick of looking at the mutant kougra in the corner of my screen all the time, so I made him ghost, because it looked cool. Then I got sick of THAT, so I made him shadow. I like the yellow eyes!
Um, anyway. His petpet is a doglefox named Feist, which literally means "a nervous belligerent little mongrel dog." This suits him perfectly.