Captain Crook promoted McDonald's Filet-O-Fish sandwich as a pirate-themed character.
Captain Crook belonged to the McDonaldland advertising universe and was associated with the Filet-O-Fish. His pirate identity provided a memorable connection between the character and a seafood menu item, much as Birdie represented breakfast and other characters represented different fictional roles.
Captain Crook is frequently confused with the Hamburglar because both were comic villains in McDonald's character advertising. Their product associations were different: the Hamburglar targeted hamburgers, while Captain Crook was linked to the fish sandwich. The distinction matters when identifying McDonald's branding from period commercials and packaging.
The character illustrates how McDonald's once used a large cast of recurring figures to give individual products their own personalities. That approach was especially prominent in the 1970s and 1980s, before the company relied more heavily on simplified corporate and product-led campaigns.