Animating a Drawing API Shape

Drawing API examples always seem to be either really simple or really complex. I’m interested in doing something fairly simple (I think). I’d like to draw an abstract curved shape with the Drawing API and animate the shape of the object to slowly change over time. Nothing really dramatic. Kind of like a lava lamp, I suppose. I understand this is done with movie clip control points but I haven’t seen any examples I can understand. I’m attaching a file showing an example of what I mean (done with manual tween in MX 2004). Thanks in advance for your help.