No, peacocks are not poisonous. In fact, they're not even close to being poisonous. In fact, they're actually quite harmless. The only thing that peacocks are capable of doing is scaring away predators with their loud cries and bright plumage. However, that doesn't mean that you should go around trying to pet them. Peacocks can be very aggressive, especially during mating season. They have been known to attack humans, so it's best to just admire them from a distance.