Rabbid Peach was the arguable star of one of the most successful modern Nintendo crossover games in Mario + Rabbids: Kingdom Battle. While at times being annoying and loud, her underlying charm and sense of humor endeared her to audiences while they were simultaneously impressed with the depth of the gameplay. Her inclusion would bring new fans of the Rabbids to Smash Bros., which cannot simply be overlooked.
Rabbid Peach has a variety of moves from her game to use as a basis for a Smash moveset. She could utilize her guns for ranged attacks, could slide into enemies to deal out damage, and could heal with her recovery just like standard Peach did in the game itself.