This series of You'll Die Laughing monster humor cards was produced in 1973 by Topps. There were 128 cards in the set.
This is actually the second trading card set to go by the You'll Die Laughing name; the first came in 1959, with nearly identical card backs. Yet a third YDL series was released in 1980, again with the same card back design. Both this and the 1980 sets were sold in wrappers and boxes featuring the title Creature Features, and many collectors still refer to them by that name. The 1959 set was issued in wrappers containing the title Funny Monsters.
The card fronts featured a black and white photo depicting a scene from a classic monster movie, surrounded by a white border along the card edges; the base of the card contained a humorous caption.
The card backs featured an unrelated, cornball-style joke, usually with a horror or monstrous connection. This was surrounded by an elaborate border made up of varioius monster characters laughing uproariously. Along the top of the card was the card number (in what is apparently the moon in the background) and the set title in large, 'creepy' lettering.
The laughing monsters on the card backs were drawn by veteran cartoonist Jack Davis.
Note: In addition to the regular release of these cards, apparently there was another, smaller release of cards very similar to this 1973 series. They are nearly identical except for the line 'Collect the Entire Series' printed on the backs. These do not appear to be test cards, but were probably meant to be distributed in some other fashion, like Topps Fun Packs, which contained a variety of over-produced product at a discount. These cards are skip-numbered.
Note also that a number of human faces appear in this set other than the 'monsters'; if some of them look a bit odd, it's because they were the faces of Topps employees (or perhaps hired models) whose photos have been superimposed on the original movie stills, not always perfectly. This was apparently done for some technical legal reason having to do with the supporting actors' faces in the original film stills.