This sound is from Homestar Runner Strong Bad Trogdor

Homestar Runner, created by Mike and Matt Chapman, is a beloved web cartoon featuring the infamous character Strong Bad. One of his most memorable adventures is his obsession with the mighty dragon, Trogdor. This hilarious and catchy song, originating in 2003, gained a cult following among fans. Though a movie or television show does not exist, you can relive the Trogdor magic by playing and downloading the sounds on the official Homestar Runner website.