World 5 (Super Mario Bros. 2)

World 5 (known as Chapter 5 in Yume Kōjō: Doki Doki Panic) is the fifth world in Super Mario Bros. 2. Like World 1 and World 3, it has a traditional grass-type theme, although some of World 5 takes place at night. This world introduces Green Birdo, the hardest form of Birdo in the game because she fires only fireballs and must be defeated using other projectiles. In Yume Kōjō: Doki Doki Panic, the boss was a repeat of Mouser, but for the Super Mario Bros. 2 version, he was replaced with a new boss, Clawgrip the crab.

The NES original has a few unique features: The Mushroom Blocks have a spotted design, which changed to the "plain" design from Worlds 1 and 3 for Super Mario All-Stars and Super Mario Advance. The underground areas have a blue color scheme that was changed to the standard brown one for remakes. Finally, the Mouser seen in Doki Doki Panic is white.