I thought combining yacht and battleship to battleyacht would do. Didn't know what else to call it.
When you look at that design, it clearly shows that when you're insane, you don't necessarily have to end up with a ship that has a displacement over 5,000,000 tons and uses 50 inch guns. It might look to be a completely normal looking ship... but when reaching the additional data, you know that the guy who created it should be taken away to the funny farm.