>>53863006Sock markings aren't exclusive to cats though, they are quite common in foxes (Japs loves those too), some dogs and even horses.
>>53863072It came from toxoplasmosis. They are meant to look like "ambiguous mammals" and Eevee's creator confirmed that.
>>53863081One of them (Glaceon I think) whimpers like a dog. I don't think the sounds mean anything though, especially how inconsistent they are with it. In the mainline games, for example, they sound nothing like dogs or cats.