Comic-Con is the ultimate destination for amazing fans in Finn hats and crystal gem bellybuttons, which is why Cartoon Network is celebrating the fan in a one-of-a-kind Fandemonium celebration. They've got big news, behind-the-scenes access, and special musical performances by the cast and crew from hit shows Adventure Time and Steven Universe. The panel features Adventure Time legends of OooJeremy Shada (voice of Finn), John DiMaggio (voice of Jake), Olivia Olson (voice of Marceline), andAdam Muto (co-executive producer), alongside Steven Universe gems Rebecca Sugar (creator), Zach Callison (voice of Steven), Estelle (voice of Garnet), and Ian Jones-Quartey (supervising director).