We are number one but it's a Waluigi parody is a short video made by SMG4. It involves Waluigi teaching Luigi how to be a villain after Luigi says that he wants to be a villain himself. As the title suggests and metioned in the description, it's a parody of We Are Number One from the children's TV show Lazy Town.
Synopsis
Luigi is sick of Mario and of being treated like a worthless hero and wants to be a villain like Waluigi, so Waluigi decides to teach him his ways, such as catching Mario.
In this video, only Waluigi is singing the song, but in the original version, it is a group of people (Robbie Rotten and a few others who want to be villains) singing the song.
This is one of the few episodes to have Luigi play a villainous role. However, he eventually has a change of heart once Mario is captured.
This is one of the shortest episodes at roughly only 3 minutes.
Ironically, between the two versions of this song, it has the villain(s) singing the song.
