Abaddon resembles a cross between a giant spider and a human skull. Its head is reminiscent of a human's upper jaw in shape with eight large, white eyes on both sides of it. Abaddon has a large vertebrate-esque mouth that sports two large fangs and a row of pointed teeth. It has two large depressions on both sides of its thorax, resembling human eye sockets, and a third one at the center resembling a nasal socket. Connecting its legs to its body are several artery-like structures. Abaddon's legs are long and spindly with pointed tips that resemble those of black widow spiders. It has an additional set of smaller protrusions on the back of its abdomen that are similar in appearance to spinnerets, and its abdomen resembles those of cork-lid trapdoor spider in shape. Abaddon's body is gray in color with crimson markings on its body and legs, as well as a large orange marking on its abdomen.