Brother Gabittas is a terran teacher on Bountiful, his subjects being history and theology.
It cannot be said with certainty that Gabittas actually exists, as he only appears in the memories of neurally resocialized marine Ardo Melnikov, who was one of his students.
Hickman, Tracy. StarCraft: Speed of Darkness. Simon & Schuster/Pocket Books, May 21, 2002. ISBN 0-671-04150-9