When the idea of doing Beanie Baby mutations and meldings other than SnailPony arose, the first one that came to mind (the sons' hivemind, not my own mind) was BearODactyl. BearODactyl actually arose from the mind of The Oatmeal. I'm not including the link to the specific BearODactyl comic here because the amount of profanity (words and ideas) that it contains might offend younger readers or their parents.
BearODactyl is a combination of Swoop the pterodactyl and Cinders the black bear. After taking Swoop apart, I had some help from older son on combining Swoop parts with the body of Cinders. BearODactyl differs from the first two mutations in that the ODactyl part is actually a removable costume. The wings are simply sleeves into which the bear inserts his front legs. The head attached to the wings is tied onto the bear's head like a bowtie not really visible here. In the wake of Halloween, I'd have to say that Cinders the bear is quite pleased with the power and prestige that accompany his new alterego BearODactyl. In fact, he looks ready to cast a spell that might determine the next mutation to help clean up the library floor. Can you say "conjoined twins"? "Wolf in sheep's clothing"? "Cat of nine tails"?