Oh. my. So, martens are little animals that are related to weasels, ferrets, and mink. At least, they are usually little. But now there are some martens who are getting a lot bigger because they have been eating deer. Let that sink in: eating deer.
As if that isn't enough, they have apparently been seen RIDING deer as well. I want to see a video of this!
Here's a CBC article about this strange situation: