Ievan Polkka is a traditional Finnish folk song that became an internet staple in 2006 through the Leekspin animation, where a chibi anime girl spins a leek to the tune. A Vocaloid cover by Hatsune Miku later spread it further on video sites. Sans, the pun-loving skeleton from Toby Fox's 2015 game Undertale, became a constant subject of fan remixes, and pairing his theme style with the endlessly looping polkka created a natural mashup that still circulates in fan edits and soundboards.