It's also on the player shields. The one the imp is riding.
I thought it was a Birdie (maybe a male with more plumage), but on closer inspection it is definitely a different beast: T.rex-like forelimbs and no wings (I know Birdie Mach I had no wings but did they replace the forelimbs?). I'm sure there is a logical explanation. Maybe they make better mounts than petz.