New Super Mario Bros. U: Frosted Glacier- Fliprus -- Fliprus Lake

The Fliprus is a walrus that likes to throw snowballs. You can freeze them with the Ice Flower, but you can't pick them up. The level has lots of water with crates floating in it. If you stand on the crates for a while, they briefly sink, then spring up, allowing you to reach new heights. There are floating Piranha Plants in the water with spike balls, so be careful when jumping over gaps. The first Star Coin is over the red Koopa on the moving brick blocks. Take the yellow platform up to a green pipe where you'll find the second Star Coin guarded by two Flipruses. Freeze them, then pound them to get rid of them. Under a ledge to the right of some crates is a 1-up in a brick block. In the water is a stack of three crates. Spring up from it and go right for the third Star Coin, which is hidden. Deal with the crates and Flipruses to reach the flagpole. This opens a path to a railroad with a bone coaster to the Rock-Candy Mines.