Piranhabon

Piranhabons, also known as Goros , are large Piranha Plants covered in goop found only in Super Mario Sunshine. They resemble the head of Petey Piranha, and roll along the ground, leaving behind a trail of goop as they do so. They can and will run over Mario without stopping if he is in their way. If Mario sprays them with FLUDD, he can clean the goop off of them, though they will still leave goop behind as they travel. When jumped on, they will splatter on the ground, leaving behind a puddle of goop.

Their name possibly comes from chocolate balls known as s, which Piranhabons slightly resemble.

In Super Smash Bros. Ultimate, Piranhabons are mentioned briefly by Viridi during Palutena's Guidance dialogue for Piranha Plant.

Trivia

 * In early versions, Piranhabons were not covered in goop and more closely resembled Petey Piranha's head.