The Halloween Freak preys on humans and a large variety of other creatures of varying size. Small creatures it grabs and restrains, piercing them with its long beak and lapping blood from them until they are drained. To drain blood from larger creatures it waits until the victim is asleep, stealthily approaching before furtively numbing the skin with specialized saliva from its tongue. Once the topical anesthetic has gone to work, the Halloween Freak then pierces the victim with its beak, generally choosing a major artery. It has been known to pierce between the ribs and directly into the aorta. As it pierces the victim it releases more of its specialized saliva, both anesthetizing and drugging the victim to put them into a deeper sleep, as well as preventing coagulation so that it may drink at leisure. Once its round belly is engorged it will cease to feed; usually this does not happen until the victim is fully drained, but if the creature can not finish its meal for some reason, the victim will usually continue to bleed out afterwards until they die from the wound.
The Halloween Freak is most active in late October as it prepares for hibernation. Some believe that the vivid orange and black coloration are responsible for the popularity of those colors at Halloween, which occurs when the freak is most active, while others believe that it is a "chicken and egg" scenario and that the Halloween Freak was probably thus named due to its coloration.