Per your clarification to my question in your OP:
Seems fine to me. This is adding something new to the concept and that is perfectly fine. And the fact that you haven't actually read the bios is actually pretty good forward thinking on your parts, because it helps establish that any likeness wasn't intentional. I would say as a just to be sure approach, write down the names and bios of all your characters, then have a trusted friend or family member take a look at the actual character bio and inform you only if a character just happens to look to similar to it's inspiration. I'd have this person list only concerns he or she see could be problematic in your character, but not why it is so with relation to the toy. For example, if your Bear character has super-strength, it's better to know that that is problematic, rather than your friend telling it's problematic because the toy's bio says it's the strongest on the team. It also adds as a check on Animal attribute association, which is a basic idea in some cultures, certain animals are associated with certain personalities as a rule (A wise owl, a slow sloth, an elderly turtle, a loyal dog, a dirty cowardly rat, a honey eating bear, ect). It also helps to check up on various animal personalities from around the world, they're not universal. For example, there are a series of Russian jokes that often revolve around that the paring off of a bear and a fox among a cast of other animals. These jokes only work to those who understand the Russian animal steryotypes (The Bear is a simple minded brute, but not an idiot, where as in the west, Bears are simple minded brutes that stupid and gullible. Similarly, the Fox in Russia is deceptive, but everyone knows it, so she can't get away with it, and usually the lone female among the rest of the animals, where as in the west, the Fox is more of a sly, cunning creature who often bests his rivals by outwitting them and getting away with it and is usually a male). The punchline to the joke where a bunch of animals are playing poker is "The Bear says 'If I catch anyone cheating, I will break her nose.'" Is funny because the Bear's threat implies he's trying to be threaten the room at large, but everyone knows its the fox alone he's threatening because he's very much aware of her tricks. It's not funny to westerners because, well, I have to go through a literary critique before I can even tell the joke. But knowing that can broaden your rational that the character is still safe.