The Phantom Express is a train for the dead. The Blind Specter is a light blue ghost with one large empty eye socket on his head, and his eyes coming out of his palms.
T-Bone is a very large skeleton, with his most notable feature being the conductor hat he wears. He also appears to be missing a tooth.
The Blaze Brothers look similar to the pistons of a train. They have large round heads being held on very thin tubes. They also have knives as teeth set.
The Head of the Train is a steam locomotive with a blue face and greyish-purple body, with his heart inside of his boiler. He is always seen with his teeth showing. After uncoupling from the rest of the train, he looks similar to a horse, with his body raised above his wheels by four legs and a tail that ends in a light-bulb.
Everyone on the train seems to take enjoyment in poking fun at the brothers dying. The Blind Specter says that Cuphead and Mugman shall count the worms that go through their corpses, T-Bone says the train's next destination is their funeral, The Blaze Brothers state that the train is exclusive to dead people, but now that the brothers are dead, they can ride the train, and The Head of the Train states that he has enjoyed the battle and "bringing the fright".
Before the battle, the Blind Specter jumps out of the train and makes an evil laugh in an attempt to scare Cuphead and Mugman.
Phase 1: Blind Specter
"I can see...into the future. You...will be...counting worms."
—Blind Specter, Death Screen
The first phase takes place at the back of the train with the Blind Specter, a ghost with eyes on his hands. He attacks by bouncing eyeballs towards the players. These eyeballs can be destroyed by shooting at them.
All while, flying pumpkins, come from either side, drop a pink ingot onto the vaults of the platform to move it closer to Blind Specter so he can damage the player(s). These pumpkins can be killed by shooting at them, and the ingot can only be destroyed by parrying. These pumpkins will appear in this phase and T-Bone's phase.
After enough damage, the Blind Specter is defeated, and the player(s) move forward to the next part of the train.
Phase 2: T-Bone
"All aboard!! Next stop -- your funeral."
—T-Bone, Death Screen
T-Bone primarily attacks by slamming his hands onto two spots that players can be on, before popping in and out another car and repeating his attack; players need to move the platform to the area beneath his head to avoid damage from the arms, or they can stand on either edge of the platform as the slam lands on the middle of the platform. Which cars he will appear next is usually middle->right->left and repeat. After T-Bone takes enough damage, the player(s) moves on to the next part of the train.
Phase 3: Blaze Brothers
"Sorry! This train is only for the dead...but we can help you with that."
—Blaze Brothers, Death Screen
Instead of flying pumpkins, ghosts come out of the smokestacks of the middle car and home onto players. When they are killed, a pink skull will drop that has a chance to move the platform, which can be parried. After enough damage to the both of them, they will melt and the player(s) can move to the front of the train.
Final Phase: Head of the Train
"What a glorious night for me to bring the fright!"
—Head of the Train, Death Screen
While the heart is being attacked, rings of bones coming from his nose will move across the screen if parallel to the players and fireballs raining down onto players, which come from the furnace.
Once the heart has taken enough damage, the train goes down.
This phase is unplayable in simple difficulty, as the battle ends after the Blaze Brothers' defeat without moving to the front of the train.
- The Phantom Train itself may be a reference to the "Swing You Sinners" ghosts. It may also be a reference to Oboroguma fused with a train.
- It may also be a reference to the Phantom Train, a boss from Final Fantasy 6.
- Inside The Head of the Train is his heart-shaped engine; at first, it can be assumed that it is made of some sort of metal, as it glows red, like metal does when it's hot. However, when he is defeated, it appears the engine is made out of glass, as it is clear and can crack, like glass. It is possible the heart is made of glass and just has a light inside.
- When going through the different phases, perpetually-smiling passengers can be seen on the train.
- While fighting T-Bone, the pumpkins that drop the pink ingots on the cart will be in front of T-Bone, but the objects themselves will be behind T-Bone.
- The Phantom Express is the sixth boss to have individual characters throughout the battle, with the others being the Root Pack, Ribby and Croaks, Baroness Von Bon Bon and her minions, Wally Warbles and his son, Rumor Honeybottoms with her policeman bee, and Captain Brineybeard with his ship.
- The faces of the Blaze Brothers look like a character in the 1930 cartoon "Swing You Sinners".
- Out of all the individuals of the Phantom Express, only the Blind Specter is seen in the good ending.
- Due to the Phantom Express being the final boss before Inkwell Hell as well as it being on train tracks, Cuphead and Mugman literally ended up on the 'wrong side of the tracks'.
- The pumpkins that drop pink ingots may be a reference to a pumpkin with wings from the Betty Boop 1933 cartoon Halloween Party.
- If one looks closely at the head of the train, shortly before he dislodges himself from the carriages, the number "4561" can be seen on the carriage behind him which may be a reference to the LEGO System train set.