"He is what you might call a "chick chaser." That, I believe, is the term for old guys who choose 'em very youthful. Old girls who like young men are called "veal hunters." Thus the English language is enriched every day." - Damon Runyon, 23 January 1927
And thus proving there have been cougars, and nicknames for them, for a long time now. I definitely prefer the term cougar, though, don't you?