The line comes from the 2001 animated film Shrek, where Shrek, voiced by Mike Myers, tells Donkey that ogres are like onions because they both have layers. The exchange became one of the film's most quoted moments and spread widely as a meme, reaction image and sound clip as Shrek humour grew online. People still use the single word on its own because it instantly recalls the full joke about layers, personality and hidden depth, making it useful far beyond the original scene.