Commandant Castor is a character in the series The Tale of Rumin.
His first head is mostly mute. When he speaks, his tone is completely opposite to his second personality.
Castor's second head is his dominant personality. He presents himself as imposing, strict and frightening. He shouts and commands at the top of his voice, putting the trainees into submission and fear.
He is also extremely unforgiving, refusing to help a "zombifying" Rumin after the squad had failed their exercise miserably, and claims similar failures will result in their death on the battlefield.
He is of the same race as Tummyhead. His first face is on his stomach and appears monstrous, speaking in a deep voice. The second one was on the head and had a caring face, speaking in a soft voice.
His body is stitched together with mismatched shades of blue. He has yellow eyes and wears a loincloth, instead of standard Plumber uniform.
- The name "Castor" and the planet name "Pollux" are a reference to the Gemini Twins in Greek Mythology. The twins were also known as the Dioscuri, hence the species name "Dioscuran".