A old movie a killer cougar is killing people. I thought the name was "the night of the cat"

Not a whole lot of info to go on in your post, but possibly an episode from the series The Virginian?

"The Virginian" Roar from the Mountain (TV episode 1964) - IMDb

Hi Just joined lookslike a good fun helpful site, I was wondering if someone would know the name of this movie, Its about a guy who has writers block and him and his fiancé are looking in a antique style store and the fiancé finds a leather briefcase and buys it for him, eventually he finds a manuscript hidden in the lining of the bag and claims it as his own and the book is published, then an old man appears and talks to him as he is the writer of the manuscript which he wrote when he was in the war, its sort of similar to murder of crows.

Hi Crazykat - welcome to the site! (In the future start your own post rather than asking a new question on an already answered, or old post. It will increase the chances of your post being reviewed! :)... ) I think you're looking for:
http://en.wikipedia.org/wiki/The_Words_(film)

Track of the Cat (1954) ?
Starring Robert Mitchum, Tab Hunter, Teresa Wright, Diana Lynn
IMDb synopsis:
A family saga: In a stunning mountain valley ranch setting near Aspen, complex and dangerous family dynamics play out against the backdrop of the first big snowstorm of winter and an enormous panther with seemingly mythical qualities which is killing cattle. An arrogant, pitiless son and a rigid, pharisaic mother side against a moral eldest son and a defeated alcoholic father while the youngest son tries to lie low, hoping against hope to persuade his family to allow him to marry a girl he has brought to visit. The girl draws venomous condemnation, and the two older brothers set out in the midst of a violent snowstorm on a dangerous mission to kill the deadly panther.

Track of the Cat (1954) - IMDb