Inky Piranha Plant

Inky Piranha Plants are enemies first appearing in Super Mario 3D Land. They resemble normal Piranha Plants, but they are black instead of red and can spit ink.

Super Mario 3D Land
Inky Piranha Plants appear mainly in the underground levels. They attack like a normal Piranha Plant, but they can also spit ink out of their mouths to cover the screen, like a Blooper in the Mario Kart series. When the ink is on the screen, Mario or Luigi cannot see very well and might run into an enemy or pit. If the player blows into the microphone, though, the ink will be blown off, removing it from the screen. They can be defeated by any attack method, just like a normal Piranha Plant.

Mario Tennis Open
Inky Piranha Plants appear in Mario Tennis Open. In Ink Showdown, a revamped version of the Piranha Challenge from Mario Tennis, they shoot tennis balls to the player, as well as ink blobs that will block their screen so it's harder to see.

Mario & Luigi: Dream Team
Inky Piranha Plants make their first appearance in the Mario & Luigi series as background enemies in Mario & Luigi: Dream Team. Inky Piranha Plants do not appear in the field due to their nature of a background enemy, and only randomly appears during battle in the later segments of Neo Bowser Castle.

In battle, Inky Piranha Plants will spit ink at the screen, similar to their affect in Super Mario 3D Land, making it difficult to see and avoid enemy attacks. Unlike most background enemies, it cannot be brought into the foreground whatsoever, and the use of a single Taunt Ball will simply knock it unconscious, rendering it unable to shoot ink for several turns. Once again unlike most other background enemies who are defeated through use of a Taunt Ball, Inky Piranha Plants can be defeated if a total of three Taunt Balls are thrown at one by either Bro.

Trivia

 * Inky Piranha Plants were apparently set to appear in Paper Mario: Sticker Star, as sprites and battle data for them are found in the game's code. They went unused in the final game.