Here's why:
* Wolf betta fish: Betta fish are a type of tropical fish, and there's no recognized variety called a "wolf betta." It's likely a made-up name.
* Alligator vulture: While there are vultures, like the turkey vulture, they aren't related to alligators. The term "alligator vulture" doesn't exist in a scientific context.
So, what's the commonality? There's no real commonality to find. The terms are either made up or misinterpretations of real animal names.