A member of the ruling tribunal of the water-breathing Aquans on the ocean planet Argo, who encounters Kirk and Spock after they are transformed into water-breathers.
Cadmar is an Aquan who appears in the Animated Series episode The Ambergris Element. He serves as junior tribune beneath Domar, the High Tribune of the undersea city on Argo.
The Aquans' laws, the ordainments, forbid contact with air-breathers, whom tradition holds to be treacherous. When Kirk and Spock are found injured after a sea monster attack, the Aquans surgically alter them into water-breathers to save their lives, and the two are later brought before the tribunes as suspected spies.
Cadmar belongs to the generation of leaders bound by the old prohibitions, in contrast to the younger Aquans such as Rila who help the Starfleet officers find the ancient records and the venom needed to reverse their mutation. By the end the tribunes accept that the ordainments must change.