Penguin

Frobisher morphs back into a Penguin. (DWM: Where Nobody Knows Your Name)

Penguins were birds that lived in cold or wet places. They mostly gathered in polar regions. Frobisher took on the form of a penguin as his wife Francine had been fond of them. He occasionaly changed between variations of the species. (DWM: Voyager)

Antarctica was often related to penguins due to their association with the continent. (EDA: EarthWorld)

Penguins were among the animals kept in a British zoo on which Cedric Matthews tested his aggression-enhancing formula. (TVC: The Arkwood Experiments)

In an alternate timeline, penguins lived on the River Nile in Egypt. (DW: The Big Bang)