Thurop Van Orman Flapjack Voice, Writer, Director Brian Doyle-Murray Captain K'nuckles Voice Steve Little Dr. Barber Voice Jeff Bennett Peppermint Larry Voice Sarah Henzler Additional Voices Guest Voice Roz Ryan Bubbie Voice S. Scott Bullock Captain Lasouarda, Dashing Danny's Twin, Merman No. 1, Norm the Constable (Candy Bandit), Patch, Sea Monster No. 4 Guest Voice Grey DeLisle Frida Guest Voice Daran Norris Dashing Danny, Merman No. 2, Sea Monster No. 2 Guest Voice Cole Sanchez Writer Piero Piluso Writer Brett Varon Writer Sean Szeles Writer, Writer Ako Castuera Writer Noel Belknap Writer John Infantino Writer, Writer, Assistant Director Benton Connor Writer David C. Smith Writer Dave Tennant Writer Tom King Writer Margaret Tang Voice Director