Gear teeth profiles still get me but once you get the profile of the hob and the motion that it follows (I'm assuming is it a straight plunge), you can use mechanism to built a series of videos (output as .BMP files) for each depth of the cut you need to make.
Behind the scenes you need a few things:
1. You will be making the cut at varying depth in the assembly. You need to decide how long you want the process for each tooth to take place. This tells you how many frames you need to capture at say 25 frames per second. If you want the full tooth to be cut in 10 seconds, you need 250 frames! You have what... 20 teeth? so that is a 3 minute 20 second video with 5000 frames.
2. Since you know the depth of each cut you can make family tables to cover the depth of each frame. You also have to decide the "cutter speed" if you want to see motion of the hob during each frame. This can be set up with Mechanism so you can go back to your 250 frames and decide how many of those frames will be cutter motion.
The hardest part of the animations is planning the storyboard. What do you need to happened with each frame. I suggest capturing the BMP files and stitching them together after you have them all captured. This makes for the best seamless animation I've found so far. You can run make several captures each with a different depth. If you want to cut all 20 teeth, you will have to rotate the gear (a few frames for that) and do it again.
I know there's got to be an easier way but I can't think of one in core Creo.