Captain Crook was the McDonaldland character introduced in 1971 to promote the Filet-O-Fish.
Captain Crook was designed as a cartoon pirate with a direct connection to McDonald's fish sandwich advertising. His pirate identity supplied an easy visual and verbal link to the sea-themed product, while his presence in McDonaldland gave the Filet-O-Fish a character-based promotional identity similar to the Hamburglar's connection with hamburgers.
The character appeared in McDonaldland commercials during the period when McDonald's was building a larger cast of branded figures. His design and role changed over time as the company revised its children's advertising. Captain Crook was eventually used less prominently than Ronald McDonald and several other characters.
He is often confused with the Hamburglar because both were presented as mischievous figures. Their product associations were different: the Hamburglar was linked to hamburgers, while Captain Crook was linked to the Filet-O-Fish.