Well of course they do but not like vampire bats or Count Dracula They are known to be somewhat ferocious and make a lot of noise which could lead to someone believing they are like the tasmanian devil They feed on smaller animals and make a racket and a mess when killing them But they aren t some sort of bloodthirsty freaks Your jackass friend is somewhat correct because blood is part of any carnivore s intake But fishers aren t bloodthirsty or do it for pleasure