—Both Black Hats, "The Perception of Evil"
Demencia is shown to be a very energetic, rebellious, mischievous, flirtatious and scatterbrained girl. She often acts without thinking first, which causes many of the group's problems. She can also be very difficult and go directly against orders or rules. Demencia is madly in love with Black Hat, much to his annoyance. 5.0.5. is usually the victim of her pranks; it is implied that this is because Demencia sees 5.0.5. as weak and timid.
As seen in The Dreadful Dawn it has been shown that Demencia has an intense cannibalistic mentality in three instances;
First: she was eating a superhero that was lowered into her pit, during her introduction.
Second: she was eating a cheerleader slowly gnawing and pulling her while wearing her lizard hood over her face when trying to lure out Sunblast.
Third: she was seen catching and swallowing an escaped shrunken Sunblast using her tongue like a frog.
Demencia's outfit consists of a navy blue vest attached to a hood that resembles a reptile, presumably a dragon, mismatched sneakers (her left shoe is red, while the right one was teal until "The Lost Cases of Rhyboflavin"—since then, she has lost it, and currently wears a black one), a tracking device on her ankle, and long, striped stockings, of which the one on her right leg is torn. She has a long, distinctive, neon-green ponytail that comes out from behind her hood, pink bang and an odd eye with yellow iris. Although usually covered by her hoodie, a spiked choker is fastened about her neck.
- Wall Scaling: In "The Portrait of Evil", she is seen to have the ability to climb walls, in a similar manner to that of a lizard.
- Instrumentalism: As seen in "The Note of Destruction", Demencia appears to be proficient in playing guitar.
- "The Perception of Evil"
- "Horribly Heavy"
- "Wearing Evil"
- "The Portrait of Evil"
- "Sculpting Evil"
- "The Note of Destruction"
- "The Lost Cases of Ooo" (cameo)
- "The Lost Cases of Rhyboflavin" (pictured)
- "The Lost Cases of Townsville"
- "The Lost Cases of Elmore"
- "Guide for an Evil Conquest"
- "The Lost Cases of the Future"
- "The Lost Cases of Beach City"
- "The Lost Cases of the Park"
- "The Lost Cases of the Tree House"
- "Q&A Black Hat Organization replies"
- "Horrible Holidays"
- "The Foul Flower"
- "Demencia wuz here"
- "Black Hat Organization: 2018 Anniversary"
- "Trap-ical Resort" (cameo)
- "Black Hat Challenge I"
- "Black Hat Challenge II"
- Her role in the series somewhat resembles Dee Dee's in Dexter's Laboratory.
- In "The Perception of Evil" and "Guide for an Evil Conquest", a blueprint for what seems to be Demencia appears in the lab, suggesting she was created by Dr. Flug and/or Black Hat.
- Further proving this, in the pilot episode, Demencia can be seen inside a glass case, which she breaks out of.
- She is likely named after the mental illness of the same name, demencia, known in English as dementia.
- Whether or not she actually has dementia is unclear.
- She makes no appearances in any of the webisodes.
- This is not because her design hadn't been thought of yet, but simply because her design wasn't fully created yet.
- Her favorite song is "Revolution 9" by the Beatles.
- Strangely, this particular song contains the famous "turn me on dead man" clue to the "Paul is dead" conspiracy.
- Demencia is around 19-20 years old.
- Given that the series is set in 2019, Demencia's year of birth could be 1999 or 2000.
- She is a fan of Happy Tree Friends.
- Demencia's birthday is on April 1st 
- Demencia's zodiac sign is Aries.
- She appears to be incomodate when Flug mention how they start to work in black hat inc in Q&A Black Hat Organization replies".
- Just before the question Demencia is smiling and relaxed just putting her feet over the table for read a magazine, and just after Flug make the comment, we see Dementia sit normally hiding behind the magazine, and with a expression of disgust
|The Characters of Villainous|
|Black Hat • Dr. Flug Slys • 5.0.5. • Demencia|
|Earl • Cam-bot • Hatbot-Sentinel • Hatbot-ler|
|Pirate • Monstrous Black Hat • Sexy Black Hat • Dark Phantom • Vanity • Metauro • Illuminarrow|