Wonder Boy was the name of the sidekick that work with Captain Sunshine on his adventures.
Chuck Scarsdale: Believed to be the Original Wonder Boy, Chuck was the Sidekick of the Original Captain Sunshine, until the latter retired and made him the new Captain Sunshine. First Appearance: Handsome Ransom.
Wonder Boy II: Believed to be the Second Wonder Boy. He was the partner of the current Captain Sunshine but was forced to quit when he turned eighteen. It was also revealed that he has multiple emotional and physical problems after being his sidekick. First Appearance: Self-Medication.
Wonder Boy III: Believed to be the Third Wonder Boy. He was never seen on screen, but he was mentioned to have been killed by The Monarch, while the latter was drinking after losing Dr. Girlfriend. His Ashes were sent to Captain Sunshine courtesy of 21 and 24. First Mentioned: Return to Spider-Skull Island.
Hank Venture: Hank Venture became the Fourth Wonder Boy after Captain Sunshine saved him from The Monarch and believed him to be an orphan. He stayed Wonder Boy for a day then quit after realizing that Captain Sunshine was trying to use him to replace his former Wonder Boy. Captain Sunshine then made Hank leave after his father Rusty Venture showed up.
Wonder Boy V: Is an unnamed boy with a Brooklyn accent that accompanied Captain Sunshine to the Clue Clown's funeral after the later died of heart disease.