Mr. Ray is the teacher of Nemo's class. He's the jolliest science master working in marine education. He is an eagle ray who believes in the practical, taking his little fishy pupils for a ride on his back to teach them about the other creatures of the seabed and singing a whole bunch of memory-aiding ditties along the way. He helps teach his class by singing the "Let's Name the Species" song. Despite his jolly personality, he is shown to be very protective of his students, telling them to hide under him when danger approaches. He takes the class on a field trip to the drop-off, much to Marlin's discomfort for his son's sake. In the end, he is seen with a newcomer student named Squirt who joins the whole class on another field trip.
Mr. Ray first appears telling his class about the Stingray migration, a journey back to home. When the Stingray show up, Dory, who was staring at the seaweed thinking about her past, accidentally gets swooped up by the Stingray swarm, knocking her out. He is last seen wishing Dory good luck on finding her parents. At the end, it is revealed Mr. Ray left his class under Hank, Destiny, and Bailey while he joined the migration.