Reclusive archaeologist who spent five years studying the ruins on planet M-113 until his death in 2266. At about 2264, Professor Crater's wife, Nancy Crater, was killed by the last surviving native of the planet, a creature that thrived on salt. Crater could not bring himself to kill the creature in retaliation, and instead formed a symbiotic relationship whereby he would provide a steady supply of salt and the creature would use its hypnotic abilities to appear as Nancy and thus provide companionship. In 2266 the U.S.S. Enterprise arrived to deliver supplies, and Crater told Captain Kirk that all he needed were salt tablets, and that he wanted to be left alone. But when an Enterprise crew member died on the planet mysteriously, Crater and his "wife" were ordered to beam aboard the starship. This allowed the salt creature to be let loose on the ship and victimize more crew members for their body salt. Prof. Crater himself was killed in the ensuing chaos.