Big Wiggler

Mega Wigglers are a sub-species of Wiggler that first appeared in New Super Mario Bros. Wii. They are five times the size of a normal Wiggler, but they are not bigger than Super Mario Sunshine ' s Wiggler, and live beneath the ground near acid pits.

New Super Mario Bros. Wii
In New Super Mario Bros. Wii, despite being enemies, Mega Wigglers can help Mario get items normally out of his reach. For this, the players must jump over a Mega Wiggler and press the or  button to do a high jump, as if they were using a Spring.

Mega Wigglers normally cannot be defeated (even invincibility is rendered useless), and they hurt Mario by running into him while on their preset paths. They can also defeat Swoopers. Also, they don't get angry if Mario jumps atop them.

Super Mario Galaxy 2
Mega Wigglers reappear in Super Mario Galaxy 2 in the Supermassive Galaxy. They appear on the Stone Tube Planet, and Mario must avoid touching them to reach the Power Star. One that appears in an angry state circles the tube towards the end. They can't be defeated, but the Co-Star Luma is able to stop them from moving and hurting Mario.

Mario Kart 7
They make their first Mario Kart appearance in Mario Kart 7. They replace the already-giant Wigglers in Maple Treeway, because the normal Wiggler is a playable character.

Trivia

 * Mega Wigglers were originally going to appear in the original New Super Mario Bros. (when a Wiggler used a Mega Mushroom) but were cut for unknown reasons. They would get angry when Mario stomps on them unlike the Wii sequel. However, an even bigger one appeared in World 7-3 in the final game.