Ghost T.

Ghost T. is a deceased Toad in Paper Mario: The Thousand-Year Door who died on the Excess Express many years before the game's setting and now exists in limbo between this world and the next (in cabin 004, to be precise). The name "Ghost T." is a pun on "ghosty", which is a diminutive of "ghost".

As with many ghosts, he is trying to resolve earthly conflicts before moving on to the next life. He lingers on the train because he left his diary in the baggage car and does not want anybody except himself to read it. Mario retrieves the diary for him and gives it to Ghost T. Soon, a column of light shines on the specter, and he begins to ascend into the next world. However, he stops partway up, deciding to stay in the earthly realm; his reason for staying is that he likes the wallpaper of his train cabin. He died on the Excess Express because the dish he ate in the dining car had a Poison Shroom in it. Ghost T.'s death did not affect the seemingly famous train, and even reading his diary (which will result in him destroying Mario with a Dizzy Dial-like animation) reveals no information, simply stating that Ghost T. "got on a train" at an unknown time and ending with the phrase "And on that train...", at which Ghost T. would appear and deliver the aforementioned Game Over.

Later on in Paper Mario: The Thousand-Year Door, Ghost T. writes an e-mail to Mario. He does so by possessing the conductor of the Excess Express, as he himself cannot hold physical objects (something he himself notes to Mario upon first meeting the plumber). Also, he somehow managed to leave a note on Rogueport's bulletin board, possibly by possessing the conductor (or someone else) yet again.

Along with Heff T., Ghost T. stays on the Excess Express for the remainder of the game.

Tattle
That's Ghost T. He's a pretty lighthearted for a ghost. But still... A ghost is a ghost!''