After a vestigial twin grows out of Peter's neck, which he names Chip, he eventually starts realizing that people like Chip more than they like him, so Peter has him amputated. However, after Peter gets into trouble, he realizes he needs Chip more than ever.
Quest roles:
Patrick Stewart(Susie Swanson (uncredited) (archive footage) (voice)), Carrie Fisher(Angela as Mon Mothma (voice)), Joshua Rush((voice))