Just a caterpillar that extends and moves like a caterpillar as it drives. And it's motorized. Wish I could add a video but I have no idea how to use the web site.
Step 1: The Mechanism
Step 2: The 2 Body Segments
The 2 are the same except one is missing a blue rod and has 4 green "legs"
Step 3: The Head And The... Butt
The 2 are the same except one has a face (DUHH!!) and missing a white rod where the mouth is.