Happy Tree Friends debuted in 1999 as a Mondo Media web series created by Aubrey Ankrum, Rhode Montijo and Kenn Navarro. It became one of the early viral animation hits, spreading through Flash portals and later YouTube with its formula of adorable animal characters meeting sudden, exaggerated cartoon deaths. The bright main theme became inseparable from that identity. Years later the tune resurfaced in memes and short-form video, where creators use its innocent sound to signal that something deceptively cute is about to go wrong.