The island is recognised as it's own sovreign nation. Jonas Junior outlawed smoking cigerettes and alchohol, but legalised marajuana and gay marriage.
The island was left in the care of Rusty Venture after his father died and he used it for storing the X-2 when he was not using it. At the end of the season, it was given to Rusty's twin brother Jonas Venture Jr along with the X-2 to make up for consuming him in the womb.
Rusty would eventually return to the island to try to steal a part for a machine that his father built, but was discovered by Jonas and The Sea Captain who decide to help them with finding the remaining parts by giving them the X-2 and XX-1.
Spider-Skull Island became the site of the Jonas Venture Jr. Museum of Jonas Venture. It was nearly destroyed by a long-dormant self-destruct device at the grand opening, but Professor Impossible managed to contain the explosion.
Season 5 Edit
Spider-Skull Island has been left to Sally Impossible due to J.J.'s passing, as per his will.