My late mother was convinced that evil cat was somehow related to a wild type species and wasn't entirely domesticated. Anyone who encountered evil cat would understand the thinking behind this because even though she was less than eight weeks old when we got her (possibly younger, possibly less than six weeks) she was never entirely tame. There was always the hint of feral about her. Mind you, that's true of a lot of cats, but evil cat did have that air of distance - and aggression. She was relentless to poor psycho cat.
Mother said that she had read somewhere about small cats that lived in Africa and had black paws. Evil cat had entirely black paws, including black pads. Evil cat also had the softest, densest coat I have ever encountered. Then reading an article on Bored Panda I found a reference to Felis Nigripes or the Black Footed Cat.
There is a lot of similarities. I could really believe that evil cat is a result of an encounter between a house cat and a Black Footed Cat. Or she could have just generally been a normal evil cat that all tabbies aspire to.