The Simpson Houseboat is a limited-time decoration released on May 12, 2015 during the Terwilligers 2015 Event. It was a craftable item during Act Three.
Bart Simpson receives threatening letters written in blood and becomes paranoid. Later Sideshow Bob reveals that it was him that wrote the death threats. Marge goes to the police and Chief Wiggum places them in the Witness Relocation Program. They are given a convertible, their surname is changed to Thompson, and they are relocated to Terror Lake. When the Thompsons reach Terror Lake, a spoof of the opening credits is played, and the family goes to check out their new houseboat.