|Release date||22 May 2012 (Update)|
|Examine||A very flamboyant White Knight.|
Sir Rebrum is a White Knight who guards the entrance to Grotworm Lair and has set up a small White Knights Encampment to do so due to his superiors thinking that the worms are a threat to Rimmington where he is in command of the white knight operation exploring the cave and assessing the danger. He falsely claims to have controlled the situation when talking to him.
He is seemingly not held in high regards by his subordinates, and is described by Sir Rinch in his notes as "a maniac" who is "only interested in his own advancement."
- His name is a pun on "cerebrum", the largest part of the human brain as well as the site for intelligence. This seems to coincide with his approach to his mission to investigate the Grotworm Lair, as he "has decided that discretion is the better part of valour."
- He seems to be suffering from insanity. It is quite possible that he has been driven mad by the events regarding his squad and the Grotworm Lair; however, he could have simply been insane from the start.