The Fishin' Boo has a cloud and a fishing pole, just like a Lakitu, but they carry a purple fire on their fishing line and the cloud is piloted by a Boo, which has goggle-like eyes, arms, and a small tuft of hair. These enemies appear in some Ghost House levels, and will follow Mario as he goes through the level, usually only in one room.
Besides their debut in Super Mario World, they have also made appearances in Super Princess Peach, Yoshi's Cookie, and Bowser's Inside Story. In Super Princess Peach, they appear in Shriek Mansion, along with a calm variety. In Yoshi's Cookie, the Gamecube version (As part of the Nintendo Puzzle Collection) has a Fishin' Boo as the fourth opponent on Hard mode in the game's VS. Mode. In Bowser's Inside Story, Bowser's level up screen has a Boo with a fishing rod.
In New Super Mario Bros. Wii, there is an unused and unfinished object which is entitled EN_GHOST_JUGEM (Jugem being the Japanese name of Lakitu). This may mean that these enemies were intended to be included in the game, likely in the Ghost Houses, but were never finished and thus never put into the game.