Very Nice.

Not necessarily a suggestion but an observation: Perhaps the eyes could simply be glasses. Not only would that differentiate him from that familiar caveman it would also ensure the toon render would have the stark difference in meshes for A:M's toon rendered to contrast.
Two odd thoughts this also brings to mind:
- This will be a nice tip of the hat to Martin and Hanna Barbera who both had a pivotal moment of history together. Barbera decided to go one way which sent Martin in another.
- This guy could start a story with an eyeglassless brute and be gifted the glasses by someone in who has arrived in a rocket.
In other words... really cool idea and model who has already inspired me to want to tell toon stories.
Some more randomized brainstorming:
- Maybe he could have a lot of 2D (on purpose) props? (An extension of this exercise might introduce filmmakers to the power of A:M's Layers and such so they could further take advantage of the look and productivity they can exploit using principles of 'limited animation')
- Perhaps he's a primitive earthing who suddenly show up on camera who doesn't know walking into a movie set on a planet circling some other star.
- He's got a girlfriend named Betsy that is superseyhot! (I always wondered what she saw in that guy)
- D. Absolutely... None of the Above
Outstanding work Robert!