OMG,  these are the cutest things I have ever made!!! I saw them online and had to make some.  The pattern I have is for just the bootie part, I had to make up the ears by trial and error.
They are made from 100%  wool then felted, after they are dry (couple days) I felted in the eyes, nose and little tail!!  I've only made one pair of these so far but have made a dozen pair or more of the plain bootie.  I will post some pics of those soon.