Prickly Piranha Plant

Prickly Piranha Plants are a purple sub-species of Piranha Plant first appearing in the game Super Mario Galaxy. They are basically bigger, purple Piranha Plants whose stem is covered in spikes. To attack, a Prickly Piranha Plant attempts to slam its head into Mario or Luigi. It can be defeated by hitting it with Stretch Plants or by stomping it after it has slammed its head on the ground. Some are necessary to be defeated in order to make a beanstalk to grow so Mario (or Luigi) can proceed.

They reappear in Super Mario Galaxy 2 with the same behavior, though they are very rare. The game also introduces a new variation called the Spiky Piranha Plant, which attacks in a similar way, but is black and cannot be stomped due the spikes on its head.