Henry

"Hello...? Uncle Arthur...? D-Dad...? Momma...?"

- Henry attempting to call out to his family before his death.

Henry is a member of the family and a non-canon cartoon counterpart to Thomas, appearing in the Christmas Special "My Two Front Teeth".

Personality
Unlike Sofia, Henry is more timid in nature and lacks the confidence to confront much of the issues the pair face. Despite this - however - he'll support Sofia when they are in certain predicaments (e.g when Uncle Arthur goes missing).

Still, he might give suggestions to the situation present but will allow Sofia to take the lead if necessary.

Appearance
Henry has brown hair, blue eyes, porcelain skin, blushed cheeks and a darkened nose. To match the Christmas-themed cabin, he also has a stripped jumper of both red and green along with stripped blue gloves.

Story
Within the beginning of "My Two Front Teeth", Sofia and Henry are seen shivering from the cold which prompts her to state "Well maybe you should get bundled up like a cute little Christmas present!" as she lifts up Ava bundled up in a blanket. Just when they are informed that dinner is ready, the doorbell rings to reveal Uncle Arthur at the door who greets her with a smile and a pencil and paper in-hand.

This prompts Sofia to sing "All I Want For Christmas Is My Two Front Teeth" by Donald Yetter Gardner, leading Martin to place her Christmas list in the mail-box before he presumably disappears within the snowy forest by an unknown entity. Gloria is also killed later on in the night alongside Martin.

On the 22nd of December, Arthur meets up with Henry and Sofia to bake cookies whilst Martin and Gloria "get well" from their unknown illness. As Arthur showcases the cookies to Sofia and Henry, each represent the family in this order: Henry, Sofia, Gloria?, Arthur and Martin. One cookie however seems horrifically burnt to a crisp, blackened and shriveled up. When Sofia comments about what happened to the cookie, Arthur briefly states "That one was imperfect-" before a jumpscare using the cartoon's introduction appears, ending the scene.

As the cartoon returns, the day ends like previously with Sofia complaining about how much she's eaten before being sent to bed in hopes of feeling better the next morning. This time it is by Arthur since Gloria is nowhere in sight.

On the 23rd of December, it shows Sofia and Henry in the living-room wondering where Arthur has gone. Just when he suggests that they should go look for him, camera footage of a room filled with Magical Sofia dolls appears instead. After this, Arthur can be heard calling out to Henry from the distance, causing Henry to leave his room to investigate the voice. When calling out for the rest of his family, he is supposedly killed off-screen by an unseen force, revealing a heavily distorted and filtered image of a Henry doll instead with distorted music to accompany the scene.

As this day concludes, another snowman is added to the collection on-screen, confirming Henry's death.

Trivia

 * Some fans/commenters assume that the voice of Arthur had been the supposed demonic entity using Arthur's voice (which might have been acquired from the night prior) to lure Henry out of his room and cause his death.
 * From the cartoon, it's never shown how Henry did die, whether it had been the demonic entity or even Martin himself (who might possibly be under the demon's control).
 * During the Magical Sofia doll segment, a strange humanoid face is seen emerging from the cluster in the room as rapid footsteps approach off-screen.