Ghost T. is the Sprit of a deceased toad from Paper Mario: The Thousand Year Door.
Story[]
Ghost T. was a passenger on the Excess Express train who had lost his diary on a trip. Apparantly mortified by the thought of anyone reading what he wrote in it, he decided to haunt the train until he found it. Due to this, he met Mario, who was on a quest to claim the Crystal Stars that led him aboard the train. Among other crisises aboard the train during Mario's trip, it appeared that there was an inconsistency with bed blankets and registered passengers, in which the conductor had to sacrifice his own blanket to make sure all the passengers were blanketed. Ghost T. was the unregistered passenger, who did not need it and agreed to return it if Mario found his diary for him and not read it. With the return of his diary, he began to move onto the next world, but deciding he was in no hurry at the last second, choosing to linger for a little while longer.
Ghost T. is not normally hostile. However, should Mario read his diary, Ghost T. will become infuriated and kill Mario on the spot. This arguably makes him the most dangerous character in the game.