The sound comes from Eduard Khil, a Russian singer whose wordless vocalise, originally titled 'I Am Glad, 'Cause I'm Finally Returning Back Home,' was recorded in the Soviet era and rediscovered online in 2009. A clip of Khil performing it on television spread rapidly across YouTube and forums, where viewers dubbed it the Trololo song and turned his smiling performance into a global troll meme. It has since become shorthand for playful mischief, appearing in reaction videos, edits and remixes long after its viral peak.