Corin is an old shepherd who offers his services to Rosalind, Celia, and Touchstone. He is moderately intelligent and is wise from experience. In some renditions of As You Like It, Corin is changed to a female character (Corrine) for various possible reasons.
Corin first appears trying unsuccessfully to counsel Sylvius in his attempts to woo Phebe. He is then hailed by Rosalind, Celia, and Touchstone, all exhausted and starving. He reveals to them that his master is selling all of his goods and property, and they agree to buy it so that they can stay somewhere in Arden. Toucstone is immediately poking fun at Corin, addressing him as "a clown." When Corin later appears, he defends the shepherd's life from Touchstone's foolery, giving several short speeches about the extent of simple knowledge. Corin also attempts to refute Touchstone's jest that he is condemned for not ever seeing court, but the clown is too nimble for him, and he gives over the attempt.
Corin does not play a significant role in any other scenes, only to act as a path between scenes by summoning other characters.