Nothing is known about Dennis's life before the apocalypse, except the fact that he had a sister named Denise, who described him as being brave, yet dangerous; it is likely that because of this behavior, this is the reason he died during the early days of the apocalypse.
This list shows the victims Dennis has killed:
- Possibly numerous counts unnamed people
- Numerous counts of zombies
His death was not explicitly mentioned by Denise, but it is known that he died during the apocalypse.