The appereance is a mix of cats and kitsunes; like Evoli/Eevee in Pokémon. In Japan, both creatures are lucky charms for its owner. Fox Squirrels are called Kitsunerisu (キツネリス) oder Mammal (マメ) in Japanese.
Nausicaä of the Valley of the Wind
A Fox Squirrel named Teto appears as Nausicaä's pet. Fox Squirrels are wild animals. However, Nausciaä managed to tame Teto.