Frosted Glacier

Frosted Glacier is the third world in New Super Mario Bros. U, lying northeast of Layer Cake Desert. Frosted Glacier is a cold and snowy world with pine trees and small indigo mountains that takes place during a constellation filled night. The boss of this world is Wendy O. Koopa. The Bubble Baby Yoshi is making an appearance in the first level of this world. So far, there are four levels, one being the Fortress, as well as a green Toad House. It's also possible that there are Cooligan Enemy Courses, as they seem to slide into a pipe near the second level.

Trivia

 * There is also a pipe at the beginning, and it could possibly be a way to get to earlier worlds or later finished worlds easier, as Acorn Plains and Layer Cake Desert has the same pipe in the beginning of the worlds.
 * This is one of the few worlds in the Mario series to take during night.