Emboo is a character that was originally created to function as the self-insert character of the author in Undertale Corrupted Justice and a few other AUs, similair to Annoying Dog in Undertale. However, later on he became a minor enemy in Unaltered after becoming second place in an OC contest, and since then, the author only somewhat considers him a self-insert, but mostly an OC.
Emboo's mother is a ghost, and his father a fire elemental, and thus he has traits of both species of monsters. His personality is heavily based on stereotypical ghost behavior, and his design is based on The Snatcher and the Litwick family.
Emboo is a ghostly purple flame, with yellow glowing eyes and a mouth glowing in the same color. His mouth is in the typical creepy zigzagging mouth shape, similar to Underfell Napstablook's. He lacks eyebrows, and instead shows expressions by changing the shape of his eyes. His Tyrannic Fell variant lacks the black pupils of his main version, having his eyes completely yellow.
When possessing something, green-blueish flames float around the possessed object.
Emboo has typical ghost quirks, loving to scare others. However, he typically does this just for fun, and doesn't mean to harm others (although he still nearly does more often than not), and he can be a bit of a dick. Other hobbies include sitting in dark rooms, reading and listening to music, which includes those of his distant cousin Napstablook. He is not very trustworthy.
As he is partially a fire element as well, he hates water, since this is deadly for him in high substances.
The Tyrannic Fell variant of Emboo has a much different personality, being very cruel, like the majority of the AU's stronger monsters, and he loves seeing others suffer.
As Emboo is partially a ghost, he has the ability to float, phase through walls and possess objects. Unlike full ghost monsters, he always leaves green-blueish flames behind when phasing through something, and these flames surround objects he possesses as well. However, an ability he does not inherit from ghost monsters is the ability to fully vanish, always remaining somewhat visible as a vague purple glow.
From his father's side, he has inherited the ability to use fire magic. This includes his own kind special kind of fire, phantom fire, which can levitate inanimate objects without burning them (it maybe can burn souls however, but he never tried).
In Tyrannic Fell, aside from these abilities, he is also able to make others see their greatest fears as if they were right in front of them. He uses this as a torture method.
Napstablook is a distant cousin of Emboo. The 2 are generally on good terms, although Napstablook often is creeped out by him and usually keeps his distance.
Emboo condiders Mad Dummy his favorite relative, though rarely interacts with her due to her living in Waterfall.
- Main article: Phantomime
In the AUs where they coexist/know each other, Emboo loves to poke fun at the fact his distant cousin never talks unless he is angry, and his "ridiculous" French accent.
- Main article: Polterzul
In the AUs where they coexist/know each other, Emboo doesn't like her very much, mostly because she is made out of water, and never visits her.
Grillby is a distant relative of Emboo, although they very rarely speak to each other (partially because Grillby is not talkative).
In Corrupted Justice, Emboo and Chara end up becoming friends at some point after the True Pacifist route. Together they prank around a lot.