The term 'Kind of Grass' can refer to several different types of grass. OAT (3 letters) is a cereal grain that is used for food and animal feed, and is also used as a cover crop. EEL (3 letters) is a type of fish that lives in both fresh and salt water. Rie (3 letters) is a type of grass found in wetland areas. CRAB (4 letters) grass is a type of grass that is often used for lawns and gardens. MANNA (5 letters) grass is a type of grass native to the Mediterranean region. Redtop (6 letters) is a type of grass that is commonly used for hay production.