The term 'Pasture Grazer' refers to animals that feed on grass and other vegetation in a pasture. Two examples of such animals are cows and ewes, which both have three letters. Cows are large, horned mammals that are commonly used for their milk, meat, and hides. Ewes are female sheep, which are often kept for their wool and meat. Both cows and ewes are important sources of food and materials for humans.