I knew you would agree! Are there any already in the comics? I just watched one of the 90's cartoons that took place in the Savage Land and there was, um, I forget his name a blonde character with a saber toothed cat name Zaboo, is Zaboo supposed to be a mutant? My photo of the doberman, amazing animals, I think the comics could use one.
I'm glad you asked! My vote for the most freakiest, violent, blood thirsty, selfish, dominant, poweful animal mutant would be the hyena. They fight eachother all the time begining at birth, killing their mates, babies and siblingd, they are bent on their social hyerarchy and have jaws so pwerful they can crush ox bones. They eat their prey while still alive and are just plain weird looking. Females are the leaders of the pack and larger, they are more closely related to a mongoose than a dog or wolf if you can believe it, maybe they are mutants! I also give good credit to the alligator or croc because they are ancient, powerful, vicious, killers who don't have a shred of sympathy. Sharks are killing machines, Honey Badgers have a high tolerance for pain and don't give a crap about anyone else. Of course dogs are the most intelligent, powerful and as close to humans as far as way of life in a human society, they are the oldest of the domesticated animals and have evolved or, mutated more rapidly than any other.