How to create an animated outline?

Hi.

For a project I wanted to create something, that resembles something like this:

  • a very detailed waterdrop
  • some kind of ooze
  • some kind of amoeba

Something like that. A roughly round organically animated thing, with a darker outline. Now I wondered how to realize this. I basically had three ideas so far.

a) I draw the outline with actionscript, using drawing function to create dynamically a shape out of curves, fill it with a fitting color and make the outline more distinct using the linestyle. The problem: I’m not sure if there is any realistic chance to also animate this without using thousands of lines of code.

b) I create several round shapes that are close to each other. All of them have the same color, and I move them slowly around, so that they look like a single shape with a curved border slowly animated. Then I add an outline by creating a thin but very strong glow effect. Problem: These filters take up a lot of processing power, and the Glowfilter will be slightly blurry (beeing a glow filter after all), which is not the effect I want.

c) I draw the shapes by hand, give them manually an outline and animate the thing using tweens and stuff. Problem: I don’t think I can animate them fluently enough that way.

Anyone got any ideas?

Or in short:
How do I in flash create something, that has a fluent organic animation and a distinct outline?

Thanks for any thoughts.