This is when a character is turned into Fun Personified or a Plucky Comic Relief in an adaptation. May be a sign of Flanderization or Character Exaggeration.
This trope is often found in Derivative Works that are Lighter and Softer or Denser and Wackier than their source. This may also come from an Adaptational Angst Downgrade (if the character's more broodier traits are downplayed or outright extracted for comedy's sake), Adaptational Heroism and Adaptational Nice Guy, in which a character's more light-hearted personality removes any seriousness they originally had, though the opposite can apply for more darkly humorous works in which the character is portrayed as a Heroic Comedic Sociopath, made Laughably Evil, or both, often with a bad sense of humor.
Sometimes this new characterization becomes more popular and is later adapted into the original work.
Sub-Trope of Adaptation Personality Change. Contrast Adaptational Angst Upgrade and Adaptational Seriousness. Compare Demoted to Comic Relief and Adaptational Dumbass.
Adaptational Comic Relief has been suggested to play 2 roles. Click below to see other actors suggested for each role, and vote for who you think would play the role best.