DUCK-BILLED PLATYPI
Though they may look like a botched happy meal toy, male platypi have spurs on their hind legs that deliver a powerful dose of venom. How powerful? The venom is not only excruciating itself, but it can leave victims with a heightened sensitivity to any pain for months.
MONKEYS
Small, mischievous monkeys like capuchins will do more than steal your car keys or throw poop at you — monkeys are so closely related to people that they can easily transmit diseases like Hepatitis C through a bite.