The Exit Crypt also known as the Mausoleum is the final scene in the Haunted Mansion
The guest's Doombuggy enters the Mausoleum at the end of the Graveyard sequence where they are immediately "greeted" by the Raven who caws at guests while perching on the door to the Mausoleum. Guest's are also now reunited with the Ghost Host who tells them to, "Beware of Hitchhiking Ghosts" and directly after this guests pass by three hitchhiking spirits; a Traveler, a Skeleton and a Prisoner. Guests are then told by their host that they have been selected by the hitchhikers to help fill the mansion's quota and that they will be haunted until they return, meanwhile the doom-buggy passes by a wall of mirrors showing that the Hitchhikers are sitting in the vehicles along with the mortals. After this, the guests pass the Ghostess (Little Leota) who tells them "Hurry Back" and "Remember to bring your Death Certificates". All the while a somber reprise of Grim Grinning Ghosts can be heard in the background, as the Singing Busts leave guests with these parting words:
"If you would like to join our jamboree
There's a simple rule that's compulsory
Mortals pay a token fee
Rest in peace, the haunting's free
So hurry back we would like your company"
Guests finally exit the Mansion's realm through a "Dead End" leading to the relative safety of the Living World.
After the guests see the Hitchhiking spirits through the mirror, they pass a sign (removed in the 2010's) that states "Dead End: Prepare to exit into the Living World" where they disembark from their doombuggy onto a moving walkway that leads to a ramp escalator. This is the part where they encounter Little Leota standing on a pedestal until they reach an archway that leads to the ride's exit. 
Walt Disney World/Tokyo version
Similar to the Disneyland version but the guests remain in their doombuggies after seeing the hitchhiking ghost and then pass underneath Little Leota, who stands next to a giant urn flanked by two flowerpots, before passing the "Dead End" sign into the exit hallway where they disembark from their doombuggy onto a moving walkway that leads to a long hallway until they reach a door to exit the ride.
The "Dead End" sign was removed in this version in the 2010's but still remains in the Tokyo version.
Leaving Phantom Canyon behind, guests enter a tunnel beneath Phantom Manor, where they encounter Melanie again, who points the way out. As the guests' Doom Buggies make their way through the tunnel, they pass by a set of gilt-framed mirrors. In the mirrors, guests see the Phantom on top of the vehicle as his evil laughter echoes throughout the tunnel.
As the Phantom vanishes from view, guests then unload from their Doom Buggies and make their way through the Manor's wine cellar.
As guests near the end of the tunnel, they find a tiny figure of Melanie who tells them to "hurry back" and to "bring their death certificates". The guests then exit into Boot Hill, a Cemetery filled with humorous gravestones, as well as ride-oriented gravestones for the Ravenswoods and several others.
As guests leave Phantom Canyon, they enter a crypt containing the bodies of Melanie's four suitors, including Barry Claude, whose hand can be seen protruding from his tomb while holding a wedding ring. Heading through the tunnel, guests ride past the mirrors, where they see Melanie appear in their vehicle as she asks them to marry her.
After unloading, guests hear Melanie's voice telling them to "Hurry back".
Haunted Mansion Holiday
For the holiday season, this scene is modified to fit with the theme of the overlay. Interestingly, the holiday variation of the Exit Crypt has gone through several iterations.
In the 2001-2002 season, the Mausoleum had guests pass by a large cut-out diorama featuring Lock, Shock, and Barrel and the three jack-in-the-boxes featured in the Attic, all while the Hitchhiking Ghosts can be seen in the background, silhouetted against the full moon as they continue to thumb a ride with the guests. As the Doom Buggies pass the mirrors, guests will see that one of the jack-in-the-boxes has hitched a ride with them while the Ghost Host bids them farewell.
Little Leota is replaced by Little Sally, who asks guests to hurry back while Jack Skellington, as Sandy Claws, flies off into the night on his sleigh.
All while this happens, guests can hear the voices of the Singing Pumpkins wishing them a "Scary Christmas" and a "Haunted New Year."
From 2003 onwards, the Crypt scene was changed to feature Oogie Boogie, the main villain of The Nightmare Before Christmas, offering up his own brand of Christmas in the form of "Oogie's Holiday Tricks and Treats". In the new scene, Oogie Boogie is seen standing next to his gift wheel, which has pictures of gifts that he intends to offer guests on the ride.
As guests pass by the mirrors, they see one of the gifts that was featured on Oogie's wheel, including a stocking full of bugs or snakes, candy cane dynamite, evil gingerbread men, and a surprise gift in the form of a Coffin with a question mark on it.
If guests get the question-marked coffin, Lock, Shock, and Barrel will pop-up from behind the mirrors to frighten the guests.
Haunted Mansion Holiday Nightmare
In Tokyo Disneyland, guests see Lock, Shock, and Barrel popping out of some presents. When passing by the mirrors, guests see that one of the trio is hitching a ride with them in the Doom Buggy. Guests then pass underneath Little Sally, who asks both the guests and Jack to hurry back. Jack, as Sandy Claws, is seen riding his sleigh into the night, silhouetted against the full moon.