Diptail was a magpie in General Ironbeak's army during the siege of Redwall Abbey. He was the brother of Quickbill and Brightback.
Diptail and his brothers were used in foraging and scouting missions, serving as the primary supply line for the army. Recognizing this, Constance and several others were able to temporarily capture the magpies for an exchange of hostages.
During the final battle, one of the magpies was killed and the other two were captured. Later, they were freed and ordered to fly back to the Northlands under the watch of Stryk Redkite.