Horatio Thomas Ernest Topper, better known as the Hatbox Ghost, is a male ghost currently haunting the Haunted Mansion.
A hunched, skeletal old man in a cloak and top hat, the Hatbox Ghost gets his name from the hatbox he holds, in which he is capable of teleporting his head (a remnant of his death via beheading). The groom of the Beating Heart Bride Emily Gracey, Hattie hides a sweet heart underneath a stone-hard shell of grumpiness and and an ego the size of a small planet. He is an expert at navigating the Endless Staircases, but, in spite of his frequent travels to other haunted locations around the world, is obsessively protective ot Haunted Mansion, and invariably lashes out against any change made to it in any way.
The son of Gregorius Topper and Annabelle Gracey, Horatio T. E. Topper was born in a poor family of Scottish decent in New Orleans. His whole family line had been composed of hatters, hatters, hatters and more hatters ever since the Middle-Ages (hence the family's rather specific family name). Horatio was a lonely, studious, hard-working child, very much unlike his rebellious younger brother Ezra, who kept trying to hitchhike his way out of town.
After the mysterious disappearance of his father, Horatio offered his brother to share ownership of the haberdashery with him. Ezra naturally refused, and Thomas took over the family business. Thanks to his extraordinary skills, he worthily upheld the Toppers' traditions, and his clients soon included the very best of society. A monarch, the King of Maldonia, even ordered a crown from him, though he never came to collect it. He grew especially fond of the wealthy Graceys, although their patriarch Vincent soon developed an antagonistic relationship with Topper, as he loathed wearing hats himself but was forced to do so by the time's customs.
Among the Graceys was Emily, Vincent's niece, with whom he quickly fell in love. He became a sort of mentor to her, giving her tips on how to navigate the high society of New Orleans, as he was quite knowledgeable on it due to his work as the rich's haberdasher. He dared not hope his love for Emily was returned, thinking himself too old for her, as he was already in his 50's at that point. Emily did in fact harbor similar feelings towards 'Mr Topper', but never acted on them either, as she was certain her surrogate father Vincent would never let her marry him anyway, both due to his lower social class and to their mutual animosity.
Engagement and Death
When Emily came to his shop in tears one day, announcing that she was being forced into marriage with a banker's son, Horatio tried to comfort her through his own sorrow at losing her. Much to his surprise, Emily eventually confessed her love to him. Once both knew of the other's feelings, they decided to get married. There was little Vincent could do, and the wedding was set to be held at Gracey Manor. However, on their wedding day, both Emily and Topper were done in by an unknown malevolent character — Topper beheaded, his head hastily hidden in a hatbox he was carrying, and Emily pushed out the Attic's window.
Horatio woke up a skeletal ghost, next to his bride, reduced to a mere material shadow still wearing her wedding gown and forever holding her bouquet and wedding candle, her heart glowing red from within her ectoplasmic chest with her broken love. Although their first years of afterlife were not easy, Horatio, who’d come to be known as the Hatbox Ghost, and Emily, the Beating Heart Bride, eventually learnt to accept their fate and have fun in the afterlife with the other ghosts who haunted the walls of Gracey Manor.
Discovering the Endless Staircase
Things went on for a little less than a century, until the early 1960's, when the Haunted Mansion ghosts were contacted by Walt Disney and his Imagineers — they wished to move the house to California, along with all of its ghosts, so they could have astounding numbers of mortals visit it daily (for a price, which they, the Imagineers, would pocket). Things dragged on until 1969; the slightly obsessional Hattie had not been too enthusiastic about the changes that were to be performed to the Mansion to make it “safe and efficient” as a ride, such as the creation of the Doombuggy tracks. So, just before the changes were implemented, Hattie took one last tour of the Haunted Mansion as he'd known it for so long. On his tour, he discovered one door he'd never seen before, which led him to the Endless Stairways — endless, Escherian, gravity-defying stairways which fascinated him.
He was quickly called back to reality — the Mansion was going to open to mortals for the very first time, and everything had to be ship-shape. Thomas made quite an impression (some would say too much of an impression; he scared some children really bad) that day. Except for one thing. His mind was not on his trick — it was on the Endless Stairways. He got tangled-up, and accidentally made his head appear in two places at once, somehow. Of course, no one but the Imagineers knew what he was supposed to do; most people just assumed his trick was to make his head appear in two places at once, and didn’t question it too much. Still, the following days, he tried to get better, but it was to no avail, his mind kept drifting back to the hidden magical room.
Desertion and Banishment
After a week or two, he couldn’t bear it anymore. He deserted the Attic and explored the mysterious Stairways for weeks without giving, so to speak, a sign of life. When he finally got back, having learnt all the secrets of the stairways, which were actually passages to other supernatural places all over the world, he was quickly summoned by the Ghost Council to their office. The problem with the head trick might have been acceptable — but outright leaving, this could not be tolerated. He was banished from his haunting grounds, to wander alone forever, far away from his bride and his friends.
Attempts to Return
But the Hatbox Ghost couldn’t cope with the loss of his home, his job and his bride. He did not resign himself. For fifty years, he kept pestering the Ghost Host, trying to get back inside the house, claiming they had no right to fire him like that (a claim that could neither be acknowledged or denied, since laws concerning ghosts are worryingly scarce). Thanks to his knowledge of the Staircases (which he kept exploring to keep himself busy whenever he wasn’t pestering the Ghost Host, allowing him to visit other haunted locations all over the world), it was child’s play for him to get back inside the building; however, he could never stay there for long, since he could not afford to be seen during the mortals’ tour until he was officially allowed back in.
Finally, after half a century of pestering and thanks to the Disney directors’ insistance (which was ignited by the large amount of fans the Hatbox Ghost had gained in the meantime), Thomas came back to the Mansion, where he took his usual spot back and resumed haunting, in spite of his enmity with the new Attic Bride, Constance Hatchaway. At first, he didn't find Emily when coming back to the Mansion. However, he was reunited with her after a few months, and, aside from Constance (whom he's still bent on getting sacked), is now truly happy.
The Hatbox Ghost is a First-Level Canon Character, as he was present in the ride when it opened in 1969, and, although he was missing for almost 50 years, has been once again featured in the attraction since 2015.