Greninja is a water-type Pokémon originally from Pokémon X & Y that serves as the main antagonist of the SM64 Bloopers episode, Revenge of the Ninja Nation. He flooded the Mushroom Kingdom to make it his home, as well as to get revenge on humanity (hence the episode name) because they polluted and later destroyed the forest he lived in to place a mall there. Ultimately, he felt sorry for his deeds and worked together with Mario and SMG4 to prevent the mall's construction. He was voiced by Billy Bob Thompson.
- It's revealed later on in the episode that Greninja's flooding of the Mushroom Kingdom was not only to get a new home; he also wanted to get revenge on humanity because they destroyed his forest to place a mall there; he was also mad because a lot of careless people dunked their trash in the pools the Greninja species lives in, polluting and killing a lot of his congeners in the process.
- Greninja is so far the only character in the series unable to speak actual words, whose vocal sounds are translated into subtitles (even if Subtitles were turned off on the DVDs).