Cat

Cats are small predatory animals that can be found at least on two different planets: Earth (the third world of the Sol System, in the Milky Way Galaxy) and Melmac (assumed to be located in the Andromeda Galaxy).

Cats are agile and clever hunters and their menu consists of all sorts of small creatures, including pests like Rats, which is why they are widely kept as pets by Humans. On Melmac, on the other hand, Cats are considered a delicacy and they are a favorite dish of many Melmacians.

It is unknown if the Earth Cats and the Melmac Cats belong to the same species.

It appears that Cats remain relitively unharmed when near Xenomorphs as seen in Alien. Although it may have thought it as a food source, But then again, the Xenomorph could easily break into the cage, so it is unknown why it simply grinned at the Cat

Sapience
Sometimes Cats are depicted as sapient beings, e.g. Dilbert Universe, Garfield Universe, etc...

Red Dwarf
The popular BBC sit-com Red Dwarf provides an interesting case of sapient cats. In the show, the protagonist, Dave Lister, is placed into suspended animation for three million years, he emerges from stasis to find that his pregnant cat has evolved into a race of humanoid beings (although there is only one known to be present on the ship)