This was recently shared on Twitter by @WolvertonComic. According to Darrell Van Citters, author of The Art Of Jay Ward Productions, the certificate and membership card were both designed by Sam Clayberger.
If you were the villain type, you could also join the Boris Badenov Fan Club. Your membership card entitled you to attend a wide variety of violent acts that were meant to be ridiculous and outlandish, like the villainous antagonist who spent his career trying to get the best of Moose and Squirrel. Unfortunately, with the real life acts of violence in the world today, the humor falls pretty flat in 2021. On a much happier note, the artwork was drawn by Allan Burns. He worked with Jay Ward in the early 60's and went on to co-create The Munsters and The Mary Tyler Moore Show with James L. Brooks (source: Art of Jay Ward blog).
