Another production problem was that, being a visual adaptation, a solution had to be found to display Zaphod's three arms and two heads, a joke originally written for radio. In a previous stage adaptation, a version of a pantomime horse was used, where two actors filled one costume, providing three arms and two heads between them. For this TV series, a radio-controlled animatronic head was designed and built, incorporating twelve servo motors and two receivers. However, the head was notoriously unreliable and in many scenes merely sits there, inanimate. For the third arm, most of the time it was seen tucked into Zaphod's jacket. But when called for, Mike Kelt, who had designed the extra head (with Joan Stribling; BBC Make-up, Hair, Prosthetics Designer) would hide behind Mark Wing-Davey and slip his arm into the appropriate sleeve.