Stonk

Stonks are poisonous cloudy enemies the appear in Mario & Luigi: Bowser's Inside Story and its remake, Mario & Luigi: Bowser's Inside Story + Bowser Jr.'s Journey. They are found in the Airway once the Dark Star enters Bowser's body to steal DNA from him, forcing Mario and Luigi to stop it.

Stonks appear as purple, Poison Puff-shaped clouds in the overworld that can partially dissipate to avoid Mario and Luigi; in battle, they immediately swell to a larger form with a black star over their eyes, and two smaller clouds that act as hands or fists. In Mario & Luigi: Bowser's Inside Story + Bowser Jr.'s Journey, their larger forms always have an angry expression, which is only used during one attack in the original game. They are usually paired with Air Cannons and Airnapses.

Battle
Stonks can attack by splitting themselves into four smaller clouds similar to their overworld forms, each of which then circle around both of the Mario Bros.; the real one's face is visible for a while before slowly vanishing, requiring the player to keep track of it and counter by hitting that cloud with the hammer. Hitting the other clouds simply dissipates them, and if the Bros. are not quick enough, the clouds will strike and possibly poison one or both of them. They can also generate a slanted vertical line of clouds that trail towards Mario and Luigi, which they can avoid by jumping in the right order; this attack can also poison either brother if they are hit.

Stonks take critical damage from the Fire Flower Bros. Attack.

In Mario & Luigi: Bowser's Inside Story + Bowser Jr.'s Journey, countering their splitting attack only deals a single point of damage.

Names in other languages
Finster-Flatulos Nube Fetida