Thanks guys.
Going to implement much of the stuff you just said.
Also putting in some small flashes (white, black, inverted, normal) just to liven things up.)
Here's what the wavy-guy's arm looks like. There's lots of bones in there, and a vector line running along it so I can onionskin the movement.
For the wave, it took me a couple hours to figure out a good one. Normally I can find what I need in Richard Williams' 'The Animator's Survival Kit' but the whip and wave action wasn't quite suitable, although I based my action on some of it.
There's countless variations. I think this is what 'rubber hose' animation is, developed by Bill Nolan. Well, its just scratching the surface.
A sine wave moves along the arm, and depending on what size, you get a different result. I put 2 kinds in - a small wave and a bigger wave. They literally are like sea waves traveling along the arms.
Keyframes for both, I think, go something like this, evenly spaced (well, that's what I used anyway):
The first is for the bigger wave. The second is for the smaller wave.