The Deus Excalibur is a magical sword imbued with the ability to fly and act on its own, and is enchanted so that it will not stop attacking its target until they are slain.
Having somehow been obtained by Scrooge McDuck during his adventuring career, the Deus Excalibur ended up in the garage at McDuck Manor. It was taken up by Dewey when he, his brothers, and Webby were menaced by Captain Pickhook, whom the sword began to attack but could not slay due to his status as a ghost. Pickhook eventually seized the sword for his own use and joined forces with the Headless Man Horse, only to be challenged by Scrooge. Pickhook attempted to kill Scrooge with the sword, but hit a statue of McDuck instead prior to being banished to the afterlife. The Deus Excalibur struck the Gong of Picchu during the battle, later contributing to the dragon's release; it was later seen flying around with Webby hanging on to the handle.
- The Deus Excalibur's name is a pun on "deus ex machina" and the legendary Excalibur, the famous mythical sword of King Arthur. "Deus" is Latin for god or deity, while the name Excalibur is of Celtic origins.