King Fuzzy (also known as Giga Fuzzy) is the leader of the Fuzzies and the first boss that Mario and co. encounter in Newer Super Mario Bros. Wii. It's fought as the tower and castle boss of Yoshi's Island.
King Fuzzy looks exactly like a Fuzzy, but bigger.
King Fuzzy will simply jump around the room. Scattered across the room will be Violet Blocks, which you must pick up and throw at it (Hammers can also work). After being hit, King Fuzzy will roll across the floor, eventually going back to its jumping state. This process must be done three times to beat the boss.