Island X is a high-tech floating castle?
Description[]
Island X is the favored lair of criminal scientist Mr X. It is a large, floating faux-medieval castle housing his lab and home, as well as his trained monkey assistant Kilgore. The Island could be steered on the high sea, ensuring the police never caught him in one place, and was camouflaged with artifical fog.
Behind the scenes[]
Island X was first seen in 1964 in The Phantom Blot Meets the Mysterious Mr X.