No , Eevee is not a Fox Pokémon
Vulpix is a fox Pokémon. Eevee's genetic is unstable
so it takes base on a lot of Animals.
Eevee is not a puppy , it is a kitten mixed with a rabbit.
Before you say it IS a fox , it has only one fox like thing.
Eevee has feline characteristics with SOME dog characteristics.
Nintendo even confirmed it they're selves.
They said Eevee was a cat mixed with little rabbit(ears) and dog-like stuff.
Eevee also can evolve into
Vaporeon , Jolteon , Flareon , Espeon , Umbreon , Leafeon and Glaceon.
A Wild EEVEE appeared!