From the Super Mario Wiki
Mad Big Boos are enemies in Super Princess Peach and can be found in the Shriek Mansion level. Mad Big Boos act the opposite of normal Big Boos; when Peach is not looking at one, it will stop moving, and when she looks at it, it will quickly move towards her. It somewhat resembles a miniature Boolossus from Luigi's Mansion.
One of the levels in Shriek Mansion has a Big Boo and Mad Big Boo, meaning that Peach will be chaed no matter which way she looks.
Like other Big Boos, they cannot be defeated by Rage.
Names in other languages
||Boo Atomique Enragé
||Enraged Atomic Boo