The phrase "big baddie" refers to a person, often fictional, who is seen as a major or significant antagonist or villain in a story or situation. Full definition
This time around, Bowser isn't the only big baddie of Minigame Island. (nintendowire.com)
In Super Mario 3D World, Mario and crew, composed of Luigi, Princess Peach and Toad, answer the call of heroism once again as big baddie Bowser is up to his no - good antics once again, capturing seven fairy princesses from the Sprixie kingdom. (glitchcat.com)
Strider gives players that same sense of excitement when building up to the next big baddie with a lifebar at the top of the screen. (shortpause.com)