It's slack-jawed and weird-looking. It's a male lion with a main, no matter what gender the character is. It more resembles a monkey in the face than a cat. Its texture is relatively low-rez and shows odd stretching in some places. It also looks bad when it sits. It's middle gets all pinched and weird. It just generally looks more like something you'd find in a Flintstones cartoon than what you'd picture a badass animal form to be.

Female cat form and male cat form are identical, with horns and manes.

Cows don't always have horns.
Female lions don't have manes.
No lions have horns.

So as you can see, it's crap.

Actually, there's a good reason that the Tauren cat form has a mane, even for females. If you look at the back of your Female Tauren's neck, you'll see that she too has a mane. It looks a bit wierd from our perspective due to real female lions not having one, but we have to remember it's a shape-shifting Tauren, not a real lion...

... Don't take this as me trying to defend the Tauren Kitty form, that thing sucks ass and deserves to be taken away and beaten with a stick. I like the idea around what the tauren catform is. A lion with gouging horns is a cool thing. But the model is of such poor quality that I just want to cry out in anguish whenever I see it and I bet a lot of other moo droods agree with me.

To those complaining of the horns on the cat form, it's because taurens have horns. If you take a good look at ALL of the night elf druid forms besides aquatic and cheetah which are shared with tauren, all of them have the night elf ears. Even the raven form. It's just a mark of you maintaining some of your character's features even shifting. Not defending the forms because I'd love to see them all refined, just pointing it out. :)