Well at least Whitney is likely not allergic to chocolate. Or teddy bears. We hope.
The polar bear girl featured here helping Peter is Tangerine, who is from Whitney's cast of created characters. She has come up with characters for both her own work and for P&C in the past, and has several more in the works that have yet to be revealed (as of this page).
In addition, thanks to the following folks who all offered up their characters for cameo positions in the background: NBBowler, Shane Lafleur, Ironmania, RayaMantayo, Furrhan, Bobby Thornbody, Arisuvix, CBFox, and Longcriercat.