|Devili. D. Koopa|
|Devili D. Koopa, Bowser's brother.|
Devili D. Koopa is a character in the game, New Super Mario Bros: The Underground. He is Bowser's brother and has 8 kids, which he calls "Devilings". He frequently kidnaps Princess Lily, but due to a higher level of protection, he kidnaps Peach instead.
Devili D. Koopa is very similar to Bowser, except has blue scales running through his whole body. His face is purple and his nuzzle is blue. He has blue hair running down his head. He wears a pair of glasses and has a devil-like tail and a pair of crimson wings.
He is somewhat similar to Bowser in terms of personality, however is a bit more successful in his plans. He is stronger, tougher, and more ambitious with his goals. However, this means that he falls just that much harder than Bowser. It is implied that after the events of New Super Mario Bros: The Underground, Mario completely tore down his kingdom and he is still in the middle of rebuilding his kingdom, even after it has been a long time. He has some history with Princess Lily, although not much is known beyond him kidnapping her to the point where she reconstructed her kingdom underground and focused on security to the point where he gave up kidnapping her.
Made his debut here as the main antagonist. He kidnaps Princess Peach and Mario and friends must rescue her. Along the way, they learn he kidnapped Princess Lily until she finally managed to drive him off, making Peach his new target to kidnap. They also learn about his eight children known as the Devilings. He is defeated in the end and his kingdom seems to be entirely destroyed as a result.
Appears as a optional boss fight in world 1. His fight involves a escalating battle as he breathes down his ice breath to freeze the platforms and create spiky and harmful areas that you don't want to jump onto, as well as sending down a variety of goofy enemies you can send at him.
Appears as a Mystery Mushroom costume.
Appears as a cameo in the Project Excalibur Storybook, as he was born to Morton Koopa Sr. after the original attack by Khrysalis.