The Feast of Fortuna is an intriguing event in Rick Riordan's "The Son of Neptune," which humorously misleads with its name. Percy, the main character, finds solace in the fact that the celebration does not involve tuna, hinting at his preference and adding a light-hearted tone to the narrative. This detail reflects the series' blend of humor and adventure, providing moments of levity amidst the epic challenges faced by the characters.