Most primates, especially simiiformes (monkeys, apes, and humans) need a ton of plants to survive. If bigfoot exists (which is pretty doubtful), then bigfoot would probably eat mostly plants. We're talking about something that most likely would occupy an ecological niche similar to bears, especially the black bear.
The dogman is a crock of shit, and nothing more. This is like discussing what impact a ghost or a fairy would have on the ecosystem. However, if it were to exist, a werewolf would probably eat a lot of meat, and act as an apex predator, similar to wolves.
