"Sock" is Tigger's cousin.
They're both orange with black stripes and have a Speech Impediment. They're also crazy, personality-wise. The only difference between them is that Sock is a real animal, and Tigger is stuffed.- Alternatively, Sock is related to Hobbes (from Calvin and Hobbes)
- Not likely, since he's a bobcat and they're both tigers.
Plato's Peak itself is the source of the animals' sapience.
Plato, Soc, Ari, and Aurora are the only talking animals in the show, and whenever we see animals anywhere other than Plato's Peak, they're inevitably shown to be non-anthropomorphic. Perhaps Plato's Peak itself has some kind of magical power that can make the animals living there more intelligent, which is why they seem to be the only ones of their kind that we see.