Bigfoot killing the poacher to protect the park ranger.
Speaking of primate cryptids, the Devil Monkeys managing to overpower and kill three armed police officers very easily. Given this is a series where most creatures (with the possible exception of Q) lack bullet immunity, that is pretty awesome.
You know who did even better than the Devil Monkeys? The Beast of Bray Road. He also took out several armed humans, but the monkeys had numbers on their side. The Bray Road monster wiped them out all on his own using nothing but speed and stealth tactics. Slight fridge horror when you consider how advanced those tactics were.
The dad of the family in "Vampire"stabbing an attacking vampire to death to protect his family.
And what does he use to achieve this? A wooden stake, of course!