Cadmus was a chimpanzee from Ape City. Eight years before Taylor's arrival, when the destruction of the Moon caused a major catastrophe in Ape City, Cadmus was one of a group of angry chimp radicals, including Prisca, who defiantly demanded greater rights from the orangutan authorities. After Cadmus was arrested and confined to The Reef, his supporters took to wearing the same red armbands he wore, as a sign of their political affiliation. Some of his former colleagues became increasingly extreme in his absence, planning to break him out of prison and purge Ape City of all non-chimps, but Siena orchestrated the freeing of Cadmus, and he began making speeches asking for reconciliation, to the disappointment of many chimps. He failed to prevent the murder of Siena, but was able to avert all-out civil war.
- Cadmus is exclusive to the continuity of the Planet of the Apes comic books published by BOOM! Studios.