Shermy is a character from Charles Schulz's newspaper comic strip Peanuts, most prominently seen in the strip's early years. He often acted as Charlie Brown's superior when it came to things like athletics. As he did not have more to his personality than that, though, he was eventually dropped from the strip in 1969.
Shermy's only appearance in a Christmas special is in A Charlie Brown Christmas. Likely reflecting his already-decreasing prominence in the strip, he is mostly seen in crowd shots with the other kids. When told that he is being cast as a shepherd in the Christmas play, he responds with his only line of the special - "Every Christmas it's the same; I always end up playing a shepherd."