A Dark Cannon is a powerful weapon used by members of the Subspace Army. This large, bulky gun resembles a dragon's head and can transform characters into trophies in an instant.
After a lengthy charging period, in which the "mouth" of the weapon glows orange, it fires a thick, black, arrow-shaped beam that instantly turns any character it hits into a trophy. The shots mostly fire in straight lines but some can curve in odd directions.
Despite its fast shot speed, Dark Cannons are not hard to dodge if the target is aware; in fact, the only times this weapon actually hits its targets that are distracted or ambushed. They can also affect only one target at a time. As a result, the victim must be quickly taken away from their partners and find a very easy escape path such as the Eggmobile to prevent an easy revival. Dark Cannons are also large and unwieldy for a normal human to carry, so only those with above-average strength can use them properly.
In the Subspace Emissary, each high-ranking member of the Subspace Army carries a Dark Cannon. The Irate Gamer uses his Dark Cannon to trophy the Angry Video Game Nerd in Real City. A false version of the Irate Gamer uses the same Dark Cannon to trophy the Nostalgia Critic in Bicycle Tracks, and almost uses it to trophy Madotsuki before Tommy Wiseau destroyed it. Dr. Robotnik uses his to trophy Mama Luigi in Sparta, and later King Harkinian in Lost Woods. Xerxes also wields one to try to trophy Leonidas in Persian Forest, but Leonidas quickly knocks it away with a spear toss. That Dark Cannon is found by Gaston, who uses it to trophy I.M. Meen, only for it to be destroyed by Harkinian. Bison attacks Guile with it in Guertana Gallery, but Ib interrupts the shot with one of her paintings. When Hitler recruits Mary as a new member of the Subspace Army, he gives his Dark Cannon to her. As Hitler explains his plan, Mary is too distracted playing with it and ends up shooting Hitler, forcing him to be revived by Günsche.