noun
maniac
MAY-nee-ak/mˈeɪniˌæk/
A person behaving with wild or dangerous intensity.
That driver races through the neighborhood like a maniac.

Etymology
Greek maniakos described someone affected with madness. The English adjective became a noun for such a person, with the broader use applying that image to someone wildly reckless or obsessive.
In context
Chze is a maniac who wants to kill everybody. >> Everybody. Yes. >> You are not safe if you are in the same room as this man.
More examples
- A maniac on a motorcycle nearly hits us.
- She works like a maniac to meet the deadline.
- Those maniacs set off fireworks inside the garage.
Forms
maniac · maniacs
maniacal adjective — Marked by wild or uncontrolled intensity.
Similar words
- daredevil
- A daredevil deliberately seeks danger, often for excitement or display.
- hothead
- A hothead acts rashly from anger rather than general wildness.