Cartoon Eyes - Auto "Squash and Stretch" Pupils

Here´s something I didn´t see in 3d yet and I think is very cool in 2d animations.... squashing pupils.

In old 2d animation this kind of stuff was used for simulating motion blur and velocity, nowadays its not necessary since late softwares are full of features to achieve those nice effects.

Well, I still like the old fashion way :) and here´s my attempt to recreate this effect with an automatic rig, so this way the animator just have to create keys for the "look at control" and the rig will create the squash based on the eye velocity.

YouTube video: