Principal Mar was a male Jedi Master from the Kel Dor species, and he held the position of headmaster at the Jedi academy situated within the Jedi Temple located on Coruscant. In his role as principal, one of his responsibilities was to dispatch welcome letters to students newly arriving at the academy. In addition to his administrative duties, he also served as an educator, imparting knowledge to Padawans in the disciplines of science and philosophy. Mar's curriculum encompassed subjects such as the scientific method, the biological characteristics of non-Human species, galactic ecology, and the fundamental principles of droid construction. He used a mask visually similar to that of Plo Koon's.
Mar's initial appearance was in the Jedi Academy novel, where he functioned as a supporting or background character.