Was it an adult, or another Muppet (Herbert Birdsfoot?) who told us the tale of the toothpaste genie.
In the story, Cookie Monster somehow released a genie from a tube of toothpaste, and the genie awarded him three wishes.
- For his first wish he asks for a big truck. A Tonka-sized model appears.
- For his second wish he requests a bigger truck, which appears as well.
- For his third wish he asks for the biggest truck of all. What seemed to be a real-life Ford F-150 pickup truck appears on the set.
CM then asked for a million cookies to fill up the back of the pickup, but the genie calmly informs him that he ran out of wishes. So CM decides to make do with what he's got: he eats the truck.
Whoever was the host, CM went up to him/her with the steering wheel and offered a bite. S/he politely refused.