When used, Piranha Plant spits a spike ball out of its mouth and keeps it airborne by blowing on it, with the ball rising and falling periodically. Piranha Plant will continue to blow on the ball until either it is launched in a direction, or the player stops holding the button, at which point the ball will be swallowed. Piranha Plant can fire the ball left or right, and if the player launches it while it is at its lowest point, it will travel further than normal. While blowing the ball, it requires damage of at least 10% damage to the spike ball to stop it. In which case, Piranha Plant will simply stop blowing it.
The spike ball has transcendent priority. As a result, Ptooie is excellent for projectile defense and gives it leverage against zoners as a result. Furthermore, the move stalls Piranha Plant's descent if used in the air. These traits make the spike ball an incredibly deadly edgeguarding tool as well. However, its damage decreases each time it hits an opponent, and after bouncing on the ground once it will lose its hitbox.
The move also makes for effective bait if the player just keeps blowing the ball, as any opponent that attempts to attack Piranha Plant directly during such will most likely have the ball drop onto them in response. This makes Ptooie a pseudo-counter of sorts, serving as a strong reversal option in disadvantage. In addition, the "loss" animation is far shorter than any other ending animation for Ptooie, which also makes it possible to combo from.
The spiked ball spit, when timed on a certain frame of the landing animation, can perform advanced techniques such as spitting the Ptooie, but doing the swallow animation (known as a “Spallow”), or doing the spit animation while the Ptooie just drops under the Piranha Plant; bypassing all soft platforms and becoming a deadly edgeguard tool against linear recoveries on stages such as Kalos Pokémon League.
The name is a reference to the Ptooie enemy from Super Mario Bros. 3. When encountered, Ptooies blow on spike balls to keep them suspended in the air, occasionally blowing on them harder to raise them higher. The move also has the same design as in Super Mario Bros. 3, as Ptooie’s appearances in recent games feature a more natural-looking spike ball. The Japanese name of the attack is the same name of the spiked balls that both Ptooies and Spikes spit out, being one of the several Japanese names for Mario enemies derived from Jugemu.
The Ptooie is also referenced in Palutena's Guidance when performed for Piranha Plant, in addition to other types of Piranha Plants.