Boo

Boos are ghost like enemies that roam some of the most abandoned of galaxies. Boos will shy away when you look a them, but they will stalk you when you have your back towards them. They can become very troublesome when in large numbers. Boos can be found on dry land and haunting abandoned waters. However Boos are less of a problem in water because they do not stalk you. Boos can be found in Haunty Halls Galaxy, Boo Moon Galaxy, and Slimy Spring Galaxy.

Defeating Boos
There is no way to defeat a Boo on land, but you can move them by an 180 degree turn by spinning into them. This is a good strategy to use when boos are blocking the path ahead of you. Boos in water can be easily defeated by shining you koopa shells headlight at them. When aquatic Boos are defeated, they release one coin each.