It's supposed to be the Germans version of the "funniest joke in the world" from the Monty Python sketch they were talking about in the previous comment. I'm pretty sure they made it nonsensical because they never actually say what the English version of the joke is lol almost all of them were fluent in German
No no no......it's the tickle monster. It's like bigfoot, 7 foot tall, hairy, and can overwhelm and overpower you. And all it wants to do is tickle you everywhere for the rest of your life.