Mega Fuzzies are enemies in New Super Mario Bros. Wii. They are a larger sub-species of Fuzzies. Like any other larger sub-species does (behave like their smaller cousins), a Mega Fuzzy behaves just like their smaller sub-species, however, they are much larger making them harder to avoid. If a Mega Fuzzy comes in contact with the player, the player will take damage or die at small form. Like normal Fuzzies, Mega Fuzzies can be defeated by being frozen from an iceball from an Ice Flower or hit by Fireballs from a Fire Flower. Mega Fuzzies, like Fuzzies, are encountered in World 7-3 and World 9-5 and World 9-8.
Two Fuzzies and four Mega Fuzzies can be seen moving along ropes (or whatever that is) in World 9-8, the last level of New Super Mario Bros. Wii. One Mega Fuzzy is behind the two Fuzzies, and the other three are on their own, separate, oval-shaped rope.
Propeller Mario is preparing to fly up to collect some Coins forming a zero. Four Mega Fuzzies can be seen to the right of him: three on their own, rectangle-shaped rope (the one with the Coins and Star Coin) and one on another rectangle-shaped rope circling some Question Blocks and Bricks. This is all in World 9-8, the last level of New Super Mario Bros. Wii.
A Fuzzy and a Mega Fuzzy move along a rectangular-shaped rope, along with some Bricks. Another Fuzzy on a separate, rectangular-shaped rope, a Star Coin, and some regular Coins can also be seen in the picture.