Brother Septimus was the antagonist from the Are You Afraid of the Dark? episode "The Tale of the Carved Stone".
For ages, Septimus had been searching for the Amulet of Ankhra. He eventually tracked it down all the way to Mr. Sardo's magic shop. But Sardo had sold it to Allison Denny, a girl who had just moved in and was without any friends. Septimus showed up at Allison's house and tried to mesmerize her into giving it to him. But Allison backed off on impulse and went right through the mirror to over a hundred years ago. There, she met up with a boy named Thomas, who was also without friends. Thomas and Alison quickly became friends, and Alison decided to bring him into the present to hang out with her. At that moment, Sardo showed up on the front door to tell about Septimus, who, at that moment suddenly appeared and threatened Sardo's life. Thomas and Allison toyed around with the crazy monk, tossing the amulet between one another. After some brief back and forth through the mirrors, Thomas put the amulet in his slingshot and sent Septimus into the mirror while simultaneously shattering it. Septimus was last seen in a shard of the shattered mirror, being sent into an unknown void.
- Septimus was portrayed by Frank Gorshin, who voiced Lysander and Marius in Diablo II.