Mega Grrrol

The large variation of Grrrols first appear in New Super Mario Bros. U along with their smaller counterparts. They are similar to Spiny Tromps from the Paper Mario series.

Big Grrrols are found in the first Rock-Candy Mines tower, Grinding-Stone Tower, in New Super Mario Bros. U, and its equivalent level in New Super Luigi U, Smashing-Stone Tower. One is also found at the end of Underground Grrrols, and a few more are found in Stone-Snake Tower. In all four levels, Grrrols are the primary obstacles. Big Grrrols generally appear in confined areas and roll back and forth as obstacles, rather than coming from generators like normal Grrrols. Like normal Grrrols, they can also smash through Brick Blocks; however, unlike them, which have twelve spikes, big Grrrols have twenty spikes.

Big Grrrols also have a chance to appear alongside Grrrols as obstacles in the Follow the Money minigame in Super Mario Party.