Coach (Super Mario Galaxy)
Coach is a tall black penguin similar to Penguru from the Sea Slide Galaxy. He is a swim instructor from the Beach Bowl Galaxy in Super Mario Galaxy, who gives advice as to the location of one of the Power Stars in that area. He can be found teaching the other penguins how to use a shell to improve their swimming. He may be the same penguin that leads Manta Ray Surfing in the Loopdeloop and Loodeswoop Galaxies, but that is not certain. Coach is shown to be the most mature of the penguins (he tells Mario to play nice and not to break the undersea wall, which Mario has to do to beat the level).
Swimming Class
Coach is the instructor of his own swimming class in the Beach Bowl Galaxy. He appears in all of the missions, though his roles are more or less minimal. In the first mission, he tells Mario that his students are being distracted by sparkly things (Star Chips). In the second mission, he offers Mario a chance to get an A and a gold medal - a Power Star - if he collects a Gold Shell and brings it to him. It is shortly after this that Coach realizes that Mario is not actually one of the Penguin students. Coach appears in the other missions, but is of little importance.
Ray Surfing
Ray Surfing is a penguin sport which is similar to our surfing, but on the back of a manta named Ray. Ray Surfing is similar to Blooper riding in Super Mario Sunshine, but the player controls ray with the Wii remote, rather than the joy-stick or the D-pad. Mario must ray surf in the Loopdeeloop Galaxy, and the Loopdeeswoop Galaxy to gain one Power Star for each challenge.
The Other Coach
Another penguin referred to as Coach appears in the Sea Slide Galaxy. This penguin is the same size as all the other generic penguins , and he is red in color. He has a bit of yellow, straw-like hair sticking out from under his swimcap. This penguin seems to be less mature than the larger Coach, and is obsessed with racing.