In, my opinion, Leafeon is based on a cat.
•Firstly, Leafeon's muzzle is a lot rounder and smaller than that of a fox, as fox's muzzles are long, and pointed.
• It has the fur colour of a Siamese Cat (except for the leaves).
•Its body is slender, and the proportions match those of a cat, as foxes have much longer legs, and are much slimmer.
•It also has the same paws as cats: They are known for walking on their toes, so as to walk lightly.
•Leafeon has feline eyes, having the characteristic slitted pupil that cats have
•It's cry sounds like a cat meowing (although I guess you can interpret it as a fox as well)
•Leafeon's tail is held high, showing another trait that is shared by cats.
I guess this is an opinion question... To me Leafeon looks like a cat.. XD
Anyway, if you read Leafeon's wiki, you'll see what other cat-like features it has: http://pokemon.wikia.com/wiki/Leafeon