Deputy Peck is Callie's trusty deputy and the deuteragonist of Sheriff Callie's Wild West. He is a red woodpecker with big yellow eyes and dressed up in a hat, bandana, boots and badge. Peck owns a mule named Clementine, whose slow, easygoing nature sometimes contrasts with Peck's character. Peck likes to eat corn and prairie peppers, but his favorite food is Trail Mix, as shown in "Peck's Trail Mix Mix Up".
Peck is loyal, honest, hardworking, and kind but in "Horseshoe Peck", he is a bad sport. He brags and boasts that he is the best at horseshoe tossing, until Callie teaches him a lesson about being a good sport. Also, in "Jail Crazy", when Callie made Peck the substitute sheriff so she can fill in for the mail, he became obsessed with the rules in his rulebook, that he sent everyone to jail for "rule-breaking". His bossiness got the best of him, though, when Billy Goat the Kid who broke out of another jail cell began looting the stores and cornered the cowardly Peck, until Callie came to rescue, and taught Peck a lesson to be nice and friendly regardless of the rules. In "Peck's Trail Mix Mix Up", he put a hole in his trail mix bag, and thought everyone was eating it. He is a bit of perfectionist and a little impatient. And whenever something goes wrong, he gets annoyed very quickly. Also, in "Parotting Pedro", Peck put Pedro in jail for imitating him, and eventually ran away. When Callie took Pedro to Echo Canyon, Pedro realized that imitating Peck made him feel silly and apologized.
Deputy Peck is generally loyal, honest, hardworking, and kind. However, he is also a bit of a perfectionist, and can be very impatient with others. In some instances he shows some other negative traits, such as Horseshoe Peck, in which he discovers the sport of horseshoes, he develops into a braggart and bad sport, and Callie has to teach him some humility.
In Jail Crazy, Peck is made the substitute sheriff to fill in for Callie. He soon became obsessed with the word of the rulebook and began to send everyone to jail for "rule-breaking". But when Billy Goat the Kid broke out and cornered Peck, it taught him a lesson in being nice and friendly regardless of the rules. In "Parotting Pedro", Peck put Pedro in jail for imitating him. In "Peck's Trail Mix Mix Up", Peck accidentally pokes a hole in his trail mix bag and begins to accuse others of taking it.