|This article belongs to the Race Against Time timeline in the Classic Continuity|
Constatine Jacobs was a Plumber who appeared in Ben 10: Race Against Time. He was assigned to watch over Eon, who was frozen in a cryogenic chamber. Eon freed himself and in the blink of an eye, Eon aged Jacobs enough to make him look like a zombie.
Jacobs' original appearance before being aged wasn't seen. However, after being aged, he had yellow teeth, white hair and his skin was a mix of grey and green. He wore a long sleeved collared shirt that was light blue.
Jacobs was found by Ben, Gwen, and Max, where he was still alive. Though he was thought to be dead, he grabbed Ben's wrist and Ben accidentally pulled off his hand, freaking him and Gwen out. Jacobs explained that Eon was after the Hands of Armageddon and also Ben himself. He died shortly after.
- Ben 10: Race Against Time (first appearance; death)