Hexiciah Steam is voiced by Dave B. Mitchell.
A famous scientist among the monster community, Hexiciah is always upbeat and enthusiastic, especially when he is immersed in his studies. He is constantly on the search for new knowledge and discoveries, and is known for going on many adventures around the world. In particular, he was fascinated by the Builders, an ancient race of monsters who created the Catacombs under Monster High
While his age is unknown, he has been alive for several centuries. 400 years ago, he assisted Elissabat in her escape from Transylvania, and helped hide the Vampire's Heart. 200 years ago, he became a teacher at Monster High after it's founding, where he became acquainted with Headless Headmistress Bloodgood, a young Mr Rotter, and a young Victor Frankenstein. He also created Robecca during this time, after getting the idea for a robot daughter from a message which, unknown to him, had been left by Robecca herself during her trip to the past.
A hundred years later, Hexiciah joined an expedition to explore an unseen section of the Catacombs. Inside, they discovered a strange machine made by the Builders and unwittingly activated it, placing them in suspended animation for a hundred years. Hexiciah eventually escaped the machine, and was reunited with Robecca, who had been searching the Catacombs for him.
His father was a human scientist. His mixed heritage is perhaps the reason for his long life. He may or may not be considered a hybrid due to his cyborg anatomy.
He is the father and creator of Robecca Steam.
Hexiciah Steam was a man with a good reputation in monster society during the late nineteenth and early twentieth century. He was a close friend of the Steins and was trusted by Dracula and Elissabat, the vampire queen.
As said before, it is implied that he and Headless Headmistress Bloodgood had a romantic relationship.
Hexiciah was entrusted with the Vampire's Heart by Elissabat, the future Vampire Queen, as she feared that her uncle, Lord Stoker, would use her as a puppet ruler to the vampires. After being entrusted with the Heart, Hexiciah installed it within his daughter, Robecca, for safe keeping, leading them back to Elissabat centuries later.
During a class on heritage in 1814, Hexiciah has to have a friendly talking to with his student Sparky, who's attempts to create life are reckless and short-sighted at best. Hexiciah invites him for a discussion after class before calling the session to an end and leaving. When a little while later he reaches his room in the catacombs, his time travel device appears used, but he pays little mind to it because he finds something more intriguing: a letter left by his daughter. The intriguing part is that he does not have a daughter, but the letter inspires him to build one. Some time later, he decides to look into the time portal too and through it reaches a laboratory in 2014, where he is greeted by his daughter and finds Sparky in tears over being responsible for the death of his own granddaughter. Hexiciah is unfazed, explaining the matter of life once more to Sparky and inspiring all students present to give a little of their own spark to return Frankie back to life. Once she's safe, he bids his daughter farewell and takes Sparky back to 1814 with him.
- Early July, 2012: Hexiciah Steam makes his diary debut in Robecca Steam's 'Between Classes' diary.
- April 02, 2013: Hexiciah Steam makes his Ghoulfriends book semi-debut in Ghoulfriends Just Want to Have Fun.
- May 06, 2013: Mattel requests the trademark for Hexiciah Steam.
- March 11, 2014: Hexiciah Steam makes his 3D cartoon semi-debut in "Frights, Camera, Action!".
- September 30, 2014: Hexiciah Steam makes a proper 3D cartoon debut in "Freaky Fusion".
- In Ghoulfriends Just Want to Have Fun, Hexiciah is constantly referred to as Hexicah. This either is an error or a preliminary name.
- Hexiciah's background has strong similarities to the character Rotwang from the 1927 science fiction film Metropolis.