Special Guest Stars Eva Marie Saint voices Katara Guest Stars Jeff Bennett voices Shiro Shinobi Logan Wells voices Meelo Darcy Rose Byrnes voices Ikki Dee Bradley Baker voices Oogi Lance Henriksen voices Lieutenant Carlos Alazraqui voices Protestor Richard Epcar voices Captain Saikhan Tom Kenny voices referee Jason Harris voices Ring Announcer Stephen Root voices Hobo Cora Baker voices 4-year-old Korra Dee Bradley Baker voices Lemur Stephen Root voices White Lotus Leader Stephen Root voices Phonograph Vendor Maria Bamford voices Pema; Fan Girl Sean Gantka voices Hasook George Coe voices Toza Richard Epcar voices Firebender Gangster