Cyborgs

Cyborgs in monster high are humans with limps replaced with mechanical parts. A cyborg (/ˈsaɪbɔːrɡ/), short for "cybernetic organism", is a being with both organic and biomechatronic body parts. The term was coined in 1960 by Manfred Clynes and Nathan S. Kline. Usually when someone becomes a cyborg in media it's usually because they were in a accident, causing them to lose a limb and having it replaced with a mechanical limb, or they do it to just upgrade their body to make them stronger then the average person.

Monster High
In monster high there are two well know cyborgs, Hexiciah Steam and Sid Borg. Sid Borg is only in the ghoulfriends books and he's powered by pistons. Sid is also a teacher at monster high, much like how Hexiciah was also a teacher at monster high till he went missing. Hexiciah is powered by steam and is the creator of Robecca Steam. Hexiciah was a grate inventor being able to even crate a time machine, it's said he went missing long a go when he was on an expedition.

While Hexiciah's 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.

Known Cyborgs

 * Hexiciah Steam
 * Sid Borg