Peace (The Unquiet Dead)

Mrs Peace was an elderly lady who died and was laid to rest at Sneed and Company... only to get right back up again and walk out the door.

Biography
An alien Gelth took over Peace's corpse, reanimating it. Peace then murdered her grandson and fled to Taliesin Lodge where Charles Dickens was giving a reading - the last place the real Peace had been intending to visit prior to her death. When the Gelth left her body to return to its gaseous form, Mrs Peace's body collapsed in the auditorium. Her corpse was taken by Gabriel Sneed and Gwyneth and placed in a coffin. Later she rose out of the coffin, alongside her grandson, Redpath and attempted to kill Rose Tyler before asking for help from the Ninth Doctor. (DW: The Unquiet Dead)