a Jekyll and Hyde
Jekyll and Hyde
A person whose personality drastically changes between good and bad. A reference to the main character in the book Strange Case of Dr. Jekyll and Mr. Hyde by Robert Louis Stevenson. Ever since Kyle became a teenager, he's turned into a real Jekyll and Hyde, and it's impossible to anticipate his mood at any given time.
Farlex Dictionary of Idioms. © 2015 Farlex, Inc, all rights reserved.
a ˌJekyll and ˈHydea person with two separate personalities or ways of behaving, one good, pleasant, etc. and one evil, unpleasant, etc: He’s a real Jekyll and Hyde. At home he shouts at his wife and children all the time; at work he’s always charming and friendly.This comes from a story by Robert Louis Stevenson, Dr Jekyll and Mr Hyde, in which Dr Jekyll takes a drug which separates the good and bad sides of his personality into two characters. All the negative aspects go into the character of Mr Hyde.
Farlex Partner Idioms Dictionary © Farlex 2017