Sir Ruber (also known as Lord Ruber or just Ruber for short) is a fictional character and the main antagonist of the 1998 animated film Quest for Camelot. He was formerly a Knight of the Round Table until he was banished from Camelot after failing to assassinate King Arthur when he was denied what he desired after serving the king for the past 10 years and went into self-imposed exile. For the next 10 years in exile, Ruber gathered men to join his cause in usurping the throne of Camelot for himself by turning them into all into mechanical barbarians via a magic potion by mixing them with weapons. His plans for taking over Camelot were delayed when his griffin lost the sword of Excalibur in the Forbidden Forest, which was stolen by the griffin, leading him to being forced to find it himself. He is based on the original main villain of the nameless Red Knight from the original book, The King's Damosel.