Gratuitous Muppet violence was a recurring theme in Henson's earlier works... And shilling for food companies was how he worked out early versions of characters like Kermit and Cookie Monster.

Here are a few more...

http://www.foodiggity.com/7-of-the-best-food-moments-in-muppet-history/

It's 'bia'. Since corrected from the original source.

Ruining a perfectly good grilled cheese... There's an app for that.

Awesomely disgusting.

The next incarnation, and a step closer to a fully-realized Cookie Monster, can be seen in this video from a 1969 Munchos commercial.

Seeing the evolution of Muppets is strangely fascinating.

http://www.youtube.com/watch?v=oEKOgOE-0b4&feature=player_embedded

Thanks for calling attention to this date. I had the pleasure of meeting Jim Henson as a kid and grew up on a steady diet of The Muppet Show and Fraggles.

I recently posted a retrospective on my site that fans might dig.
http://www.foodiggity.com/7-of-the-best-food-moments-in-muppet-history/