Mom Piranha is a giant Piranha Plant that appears in Mario & Luigi: Superstar Saga. During the events of the game, it takes up residence in a large egg on the runway at the Beanbean International Airport. She sends her offspring to take root in the runway, preventing planes from landing or taking off. Thus, Princess Peach, who is going to attend an important meeting with Queen Bean and Prince Peasley, is unable to land her plane. It is up to Mario and Luigi to get rid of the enemies. To achieve that, Mario has to drink water from one of the nearby fountains and spit it on the Piranha offspring, soaking it and making it swell up and turn a dull turquoise color. Luigi then has to shock the plant with his Thunderhand. Since the offspring is connected to Mom Piranha, the electricity surges through the roots of the Piranha Plants and into her egg, causing it to crack open, one bit at a time. When the egg is destroyed completely, Mom Piranha is revealed, and talking to the beast initiates battle.
Mom Piranha is a stubborn foe, but she is fairly easy once the brothers learn her tricks. The enormous plant is always protected by two Piranha Plants, who act as distractions and extra attacks for the boss. If the plants are destroyed, Mom Piranha will create new ones. The colors also follow a mechanic: for each Piranha Plant on the field that is the same color as Mom Piranha, she will heal 10 HP. Mom Piranha is vulnerable to Hand attacks. If she is red, Thunderhand is effective, Firebrand if she is blue. However, the opposite element will heal her, and the Piranha Plants are granted extra attacks is their leader is wounded. Mom Piranha has two attacks: She will spit a blue ball that must be hammered back and will damage all enemies if successfully countered, or she will swipe will one of her tentacles. The tentacle sweeps back and forth and must be jumped over twice. The best strategy is the brother who she is currently weak against to attack with Hand powers, while the other Bro fights the Piranha Plants, leaving alive those who are the opposite color to her.
Upon victory, the Piranhas stop spawning, and the Princess and her entourage finally land on the royal jet.
 Names in other Languages
|Mother Pakkun (Pakkun Flower being the Japanese name of Piranha Plant).
- Mom Piranha looks like Megasmilax and Lava Piranha from previous Mario RPGs.
- In the US version of the game, if the Mom Piranha is defeated when she is purple, she gives out no coins.