Ruber (voiced by Gary Oldman) is a deranged ex-Knight of the Round Table and the main antagonist in Jaden and the Quest for Camelot. After killing Sir Lionel, he tried to kill King Arthur, but Arthur warded him off with Excalibur. Ruber then made it his mission to oust King Arthur and obtain Excalibur for himself. He turned all of his soldiers into "iron men with hands of steel" and forced Juliana to take him to Camelot. However, he ended up defeating himself when he accidentally stuck Excalibur into the stone and disintegrated.
- Ruber will become Jeffrey's enemy in Jeffrey & Friends Go on the Quest for Camelot.
- Ruber will return for revenge in Jeffrey & Friends in Fantasmic!.
- Ruber will return for revenge in Jeffrey, Jaden, Hiccup & Friends meet Coco.
- Ruber is a member of the Scourge.
- Ruber will become Sonic's enemy in Sonic Storm Adventures of Quest for Camelot.
- Ruber will return for revenge (as a ghost) in Sonic Storm Adventures of Anastasia.