As a kid I would occasionally see this Black Cat image associated with certain films. It clearly meant "no kids allowed." It would be seen on movie posters and tagged with trailers for films that I was not old enough to see. When I got into my early teens I remember being brought into films that were R rated, but my parents felt were important enough to let me see.
I have not seen the cat logo as an adult, nor any of the little shorts that used to play before the film. I did some digging to find out where the cat got off to.
It turns out that the "Restricted Cougar" is an original creation of the British Columbia Film Classification Office. Developed in the 1970's under the direction of BC Chief Censor Ray MacDonald, the cat logo was part of an emerging demand for an informative rating system both in Canada and the United States. A cougar was chosen for its dramatic presence, and also because it is the largest wild cat native to BC.
I had not seen it in Alberta because it was governed by a different guide, and changes to the classification guide in the 80's and 90's to include NC-17 and 18A classifications reduced the "R" Cougar to footnote and memory.
The BC film classification website has the quicktime files of the old trailer series that was shown before R rated movies. They were produced in 1989 by former BC Film Classification director Mary-Louise McCausland and veteran NFB animator Hugh Foulds.
For your viewing pleasure: