Flippin' through my MAD paperbacks over the weekend, and buried inside one collection I found a Topps Funny Li'L Joke Book from 1970. I must've been using it as a bookmark back in the day and just forgot about it, because I seriously haven't thought about these things in decades. It's basically a small piece of paper folded in half (about the size of a trading card) to create 4 pages of silly art and jokes. Topps produced 44 in all, everything from Nutty Proverbs to Moron Jokes, and wrapped them in wax packs with a stick of flat bubble gum. (Scans at 600%!)
I found a helpful site called Sam's Toybox, and apparently he has all 44 of them. You can check out all the covers and a single, low quality sample page from each by clicking HERE.
And here's what the original Topps wrapper looked like too: