Because Nancy Kruse served as assistant director in this episode, director David Silverman was granted enough time to do his own animated sequences for the episode - including a Grandpa scene and a Frink scene. It was one of the last episodes in which he both directed and animated. The scene where the Homer clones fall into the gorge was supposed to be a reference to a similar event in the season two episode "Bart the Daredevil", but the idea was dropped due to time constraints. In preparation for the song sequence, David Silverman spoke to show composer Alf Clausen to write music for the team to animate ahead of time, to ensure the timing of the build-up and the song itself was working. Kevin Curran watched all the different film versions of "The Island of Doctor Moreau" before making his segment. The scene where the eyes eat the other eyes in the third segment was pitched by David Mirkin after the table read. After realising they had to populate the island with characters, the team hurriedly drew up many new designs for the animal-equivalents (based on similar features the character had to an animal) and sent them off to get animated. Kang and Kodos were not originally in this episode, but they were later added in to keep with the tradition of including them, whether a whole segment or a small cameo devoted to them.