From the Super Mario Wiki, the Mario encyclopedia
"Fog" redirects here. For information about the obstacle that first appears in Super Mario 64, see toxic cloud. For the obstacle that first appears in New Super Mario Bros. Wii, see poison fog.
Mist covering the stage

Mist, also known as fog, is a cloud stream found in battle in Paper Mario: The Thousand-Year Door. If mist appears, it will make low attacks harder to block with the Action Command. It is also similar to the dizzy, confused, and dodgy status effects since attacks, including projectiles, may miss their target. It is, however, still possible to do a stylish move with a hammer attack. If Admiral Bobbery, one of Mario's partners, uses Bomb, Bob-ombast, or Appeal the fog will disappear. Flurrie, another partner, can use Gale Force to blow away the mist. Additionally, it will go away if the battle takes too long or enough attacks miss.