The actor’s son, Magnus Ferrell, recently took to TikTok to share a hilarious video of his dad hopping on stage with his infamous cowbell. The 55-year-old joined his 18-year-old son and his band at a show benefitting the Cancer for College event, per Rolling Stone magazine. The charity was founded by Ferrell’s former roommate Craig Pollard. The group opened for the Psychadelic Furs, and while the crowd was enjoying the set, they were treated to a surprise cameo from the Elf star, who came out playing the cowbell from a memorable Saturday Night Live sketch that aired in 2000. As he played the instrument to the beat, the audience roared in excitement. Magnus embraced the moment, sharing a clip on TikTok as the text on the screen set the tone. “So I was playing a show…” it read, continuing, “then this dude with a cowbell shows up??” “Bro was vibing” it concluded, along with the skull face emoji, as the camera panned to Ferrell getting really into his performance. Magnus captioned the post, “everybody needs more cowbell,” a reference to the sketch that also starred Christopher Walken as a producer who urged Ferrell and his band to add “more cowbell” to a track they were recording in the studio. Magnus is a budding musician who has released a handful of singles so far, including “Back to Place,” which is the song that the band was performing when Ferrell showed up. According to the outlet, the band also covered Radiohead’s popular single, “Creep.” Magnus also shared some photos from the show to his Instagram page, with the caption, “damn that was fun.” In addition to snaps with his bandmates—Gabe Yaron and Noah Rinker—the photographer also captured the sweet embrace between Magnus and his dad backstage.