Calyx was a Cardassian male, the martial docent at the Bamarren Institute for State Intelligence. Calyx was a gnarled old man with one glass eye, it was rumored amongst the students that he had been a Gul but was demoted due to his insistence for fighting alongside his men rather than taking a privileged back seat.
Calyx is in fact the man's nickname amongst the students; a Calyx, in Cardassian mythology, is the name of an energetic multilimbed creature. Calyx reflected this in his mastery of Strategems - Cardassian physical and mental combat moves where each part of the body works independently. (DS9 novel: A Stitch in Time)