I am currently trying to grow, something like tentacles out of an object. The approach I took was to extrude along a curve, unfortunately I did not find a way to animate this as it was growing. If I select the actual CV's of the curve to animate them I end up oevrbending the geometry and I get a lot of artifacts.
I tried the same thing with a nurbs curve, which was a lot better in terms of animation but not in terms of texture as maya seems to change the number or distribution of isoparms while my surface grows and well it looks kinda crap.
I also had a look at hair, as this would be perfect to drive my tentacle, but I didn't find a way of controling its length.