Boo

Boo was introduced in Super Mario Bros. 3 as an enemy, and since then has appeared as a playable character in many games. There have been many variations of Boo introduced throughout Mario's adventures. These include Big Boo, King Boo, Boolossus and numerous others.

The most recent game that Boo has appeared in is New Super Mario Bros. for the Nintendo DS. Here, there were many levels with different types of Boos.

Appearances
The species has also been a regular playable character in the Mario Party series recently, first appearing as a playable character in Mario Party 5 for the Gamecube. In the Mario Kart series, he is an item that will not only make you invincible, but will also allow you to steal a random opponents item. It should also be noted that King Boo was a playable character in Mario Kart: Double Dash!! for the Gamecube, though he had to be unlocked. In the Gamecube game Mario Golf: Toadstool Tour, a Boo was a playable character that would be unlocked if you collected fifty birdie badges. He was also a playable character in Mario Tennis and the sequel Mario Power Tennis. In Mario Power Tennis, he was able to summon tons of Boos that would all hit the tennis ball making a very powerful hit. He also was a playable character in Mario Hoops: 3-on-3 and a team member in Mario Strikers Charged.

Types of Boos

 * Boo: These turn invisible when faced. Trick them into visibility and jump on them.
 * Boo Diddly: These will chase you when you turn your back.
 * Stretch: These boos make a platform and circle around it.
 * Fishin' Boo: A fishin' Lakitu boo. Instead of a 1-Up its extending a blue flame.
 * Boo Guys: These enemies like dropping es from their safe perch.

From Nintentown