Maluigi

Maluigi is a a clone of Luigi made similarly to Waluigi. However, instead of Luigi being mixed with Wario's DNA, he was mixed with Mario. This caused the creation of Maluigi, not Mario's brother, but the Mario equivalent of Luigi in the same way Waluigi is the Wario equivalent of Luigi.

The Ma Machine
One day, a malfunction in the Wa Machine when Mario was pushed in caused it to become the Ma Machine. When Luigi was pushed in, Maluigi was born. Wario couldn't let this happen, so he promptly fixed it. Maluigi then asked the Mario Bros. if he could be their brother, but they felt awkward letting this strange clone join them. Soon, Mario told him that he felt like Luigi was the true Mario equivalent of Luigi and that Maluigi should try to find his own meaning in life. However, Maluigi couldn't let it go. This began his tragic spiral into insanity. All of those years of job hunting only reinforced Mario's cold words. He wasn't supposed to exist. Who needed him when Mario and Luigi already existed? Soon, he decided that if he had no place in this world, Mario and Luigi didn't deserve one either. And so he became a villain, hell-bent on destroying Mario and Luigi.