Extrude animation help

I am quite new to blender…

I am trying to create a simple animation of a sphere growing legs.
I am wanting to extrude a few of the faces to do this, i was planning to keyframe each step, but this doesnt seem to record the changes that i make.

If anyone could point me in the right direction of how to achieve this it would be much appriciated.
Thanks. :confused:

one way would be to use shape keys:
i would do this “backwards”, so first model the legs.
then add couple of shape keys for the mesh. one for middle of growing phase, and one thats just round sphere with no legs at all.
the animate shapes using ipo curves for shapes, or drive them with bones.

more information about shape keys here:


Thankyou, looking into it now…