Boothead Pete was presumably a male anthropomorphic cat.
Peg-Leg Pete's great-grandfather, Boothead Pete was the head of a gang of Wild West masked robbers. They ransacked a small town near Carbine Canyon only to be chased off by its sheriff, Donald Duck's own great-grandpa Bluffer Duck (causing the town to be renamed Duck's Bluff). Boothead split off from his gang and ran away, but never dared to return for the buried loot. He later consigned his recollections of that fateful night in a chapter of his autobiography-cum-criminal record, Dastardly Deeds.
Behind the scenes
Boothead Pete is mentioned in the 1959 story Duck's Bluff Story.