What is a caterpiggle?

I came downstairs one evening and my toddler, EvilGenius ("EG") and my spouse, Masher, were ROTFL saying, "Caterpiggle! Caterpiggle!" I don't know what they were talking about but I drew a caterpiggle, thinking it probably looks like a caterpillar with a pig face. Since EG can pronounce "caterpillar" I thought he was just being silly and clever. As it turns out, it was from a Caillou episode in which the little bald boy helps his little sister Rosie overcome a fear of insects. Oh well, too late, it's now my blog title. I hope the Quebecois producers of Caillou don't mind.