Special Guest Stars John Goodman voices Robot Santa Claus Conan O'Brien voices Conan O'Brien's Head Guest Stars Phil LaMarr voices Hermes Conrad Lauren Tom voices Amy Wong Phil LaMarr voices Lionel Preacherbot Phil LaMarr voices Homeless Robot #2 David Herman voices Skier David Herman voices Weapons Shop Clerk David Herman voices Pet Shop Clerk David Herman voices Homeless Robot #1 Uncredited Frank Welker voices Nibbler Frank Welker voices Parrot