What we need is for both animals the tail to move slightly and smoothly (no more than 1cm movement), like a cat's tail AND ears to twitch.

The example svg displayes an example how a small part of the svg moves.
Here is a more elaborate example : http://codepen.io/azevedo-252/pen/rVvMXX

original.html is base file to work from. Work needs to be done in CSS (and JS only if necessary)

It will be used within a mobile application