Weasel

ForestWander.com

The "fisher cat": ferocious predator of house cats whose bloodcurdling screams pierce the dark of night. Facts about this one wildlife species have mutated a long way into fiction. For starters, fishers are members of the weasel family—not feline. Properly referred to, they're "fishers," not "fisher cats." 

The Maligned Fisher

Feb 22, 2013
ForestWander.com

The "fisher cat": ferocious predator of house cats whose bloodcurdling screams pierce the dark of night. Facts about this one wildlife species have mutated a long way into fiction. For starters, fishers are members of the weasel family—not feline. Properly referred to, they're "fishers," not "fisher cats." 

As for all the house cats they're thought to kill, here's what a NH Fish and Game species account says:

 

Before we go today, we wanted to leave listeners with a little taste of Easter magic to come.  Last month, we spoke with Erika Eichenseer, she’s the cultural curator of Prinz Rosszwifl, a recently published personal collection of five-hundred lost fables and fairy-tales discovered in a German archive.  Most of us are well acquainted with the tradition of the Easter Bunny, Erika regaled with the tale of supernatural animal we don’t usually associate with the April holiday - we’re calling it “The Legend of the Easter Weasel”.