this island earth (1955)

Neutron.
Cat (who I believe is Orangey) hangs around a science lab, in this sci-fi classic. "We call him Neutron because he's always so positive."

comedy of terrors (1963)

Cleopatra.
Rhubarb (or Orangey, as he is usually known) gets a credit and stars as the cat that lives in the undertakers shop with Vincent Price, Peter Lorre and Boris Karloff. He is seen at various times watching events patiently, and even travels on the hearse to funerals.

i, monster (1971)

Unknown.
Christopher Lee's character injects a drug into his pet cat, which goes mad, trashing his laboratory, before he then kills it.
Later Peter Cushing walks about his apartment whilst stroking a tabby.

las vegas hillbillys (1966)

Unknown.
White cat that Jayne Mansfield carries with her whilst driving!

mars attacks (1996)

Muffy.
Stuffed cat doted on by pensioner Florence Norris, who accidentally stumbles on how to kill those pesky aliens.

bringing up baby (1938)

Baby.
Baby Susan Valce's pet leopard, which gets mixed up with a wild leopard who has escaped from a zoo, in this romantic comedy farce.
The cats real name was Nissa.

rhubarb (1951)

Rhubarb.
An eccentric millionaire leaves his fortune, including a Baseball team, to a feral cat, he had adopted. The teams publicist Eric Yeager (Ray Milland) has to convince the team that the cat is good luck, whilst trying to keep Rhubarb's wilder side in check, and his fiance (who is allergic to cats), from leaving him. A screw-ball comedy that ricochets around at frightening speed as Rhubarb cause chaos to everyone around him.
The first appearance of Orangey, who went onto star in Breakfast At Tiffany's amongst others.

Sue-Lynn.
A longhaired white cat who with her two sisters sires lots of kittens with Rhubarb at the end of the film.