Prentice (Army of Ghosts)

Granddad "Prentice" was the father of Jackie Tyler and the grandfather of Rose Tyler and Tony Tyler.

He smoked and died from a heart attack in 1997, but according to Jackie in 2007, came back as a friendly ghost. This ghost was actually a Cyberman that was passing through the Void to reach N-Space. (TV: Army of Ghosts)