The Black Water Mist had belonged to Garlic, but following Garlic's imprisonment and death, Kami hid it at The Lookout. When Garlic Jr. takes over Kami's Lookout, he finds and releases the Black Water Mist. Anyone who breathes in the mist has the evil in their heart drawn out and becomes a demon-like vampire, and worships Garlic Jr. and the Spice Boys. Largely because of any inhibitions preventing evil in their heart being wrecked from infection, infected people also end up displaying seemingly superhuman elements that they aren't normally capable of possessing such as endurance and reflexes, which is demonstrated with Bulma. In addition, anyone bitten by one infected by the mist becomes exactly like them. If kept unchecked, the Black Water Mist's effects would be irreversible after twenty-four hours. The only thing that can negate the Black Water Mist is the Sacred Water. However, even the Sacred Water will be useless after 24 hours. Noticeable physical effects of Black Water Mist infection include noticeably increased incisors as well as their irises turning pink and having their pupils vanish (though the latter effect can be obscured with dark eyewear, as demonstrated by Master Roshi).
The only known way to evade exposure to the mist is by containing oneself in an area where the mist cannot pass through such as a sealed-in cave (demonstrated via Icarus throwing Gohan into a nearby cave and sealing the cave shut with his body) or otherwise by diving deep into a body of water such as an ocean (as evidenced by how Maron and Krillin unknowingly evaded the mist).
Video Game Appearances
In Dragon Ball Z: The Legacy of Goku II, certain areas of Earth remain unpurified of the Black Water Mist after the Garlic Jr. Saga which is first noted by Gohan. Though the mist has no effect on the main characters, Gohan notes the local animals in these areas have become hostile and since they've been infected too long he decides it is best to exterminate them to protect innocent animals and people which he notes will also serve as a form of training. These infected areas are indicated by a Black Water Mist Jar icon that appears on screen.
In Dragon Ball Heroes, the mist is represented by the ability Aqua Mist used by Garlic Jr., that permanently reduces the Stamina recovery of enemy supporters. The ability is also used by Spice as a boss during the Garlic Jr. Saga.
- When Piccolo was infected with the mist, it didn't have an effect on him, because Namekians are immune to the mist (though if they are, it contradicts Spice's line "Piccolo's Namekian body is having a strong reaction to the venom" although this appears more as an observation rather than a fact, and he could be mistaken).
- It's implied that the Black Water Mist can affect pure-hearted people, as Chi-Chi, who had enough purity of heart to ride the Flying Nimbus as a child, was shown to be as affected by the mist as the others.