Wanted to confirm my 2 year old memory that I thought the kids' mom was sickly or something at first, and yeah, she just looked like this. Like a gangly skin and bones rat.
Mort looks so much like her. He got dad's face cover and bass player goatee in the fur, but her spindly weird body, the not-all-the-way-around striped tail, and The Sleeve, he is a momma's boy so much.