Roy Koopa is presumably the third oldest of the seven Koopalings, the seven kids of Bowser who appear in several Super Mario games. He is seen in the Mario cartoons as Bully Koopa. However in the manga he is known by his actual name.
Super Mario Bros. 3
Roy is the fifth Koopaling to be fought. He is encountered in an airship at Sky Land. His fighting style consists of trying to crush his opponents with ground shaking stomps. Once defeated, he runs off, leaving behind the wand he used to transform the king of Sky Land.
Super Mario World
Again, Roy is the fifth Koopaling to be fought. He is fought in a room where the walls are steadily closing in, and often comes onto the ceiling. His attack style is simliar to that of his brother Morton. To defeat him, as in Super Mario Bros. 3, Mario must jump on him three times. Once defeated, he spiraled into the distance and exploded in a cloud of smoke.
Mario Luigi: Superstar Saga
Roy returned in Mario & Luigi: Superstar Saga, working for Bowletta in Bowser's castle. As usual, he is the fifth Koopaling to be fought. Once defeated, he apparently dies like the others, and vanishes.
Super Princess Peach
Although not actually seen in the game it was revealed that Roy along with his other siblings (excluding Bowser Jr.) were to make an appearence in this game but were taken out for no apparent reason. Every one of the Koopalings had their own complete sprite sheet.
New Super Mario Bros. Wii
Roy reappeared in New Super Mario Bros. Wii. This time, he is the second Koopaling to be fought. Like the others, he is fought twice per level. The second time he is fought, Kamek casts a spell making the battle reminescent to Lemmy's from Super Mario Bros. 3. Once defeated, Roy fell off the screen, but survived, as he was seen alongside Bowser, Bowser Jr., and the other Koopalings, before Bowser's castle fell on top of them and crushed them.
At first glimpse, Roy is a muscular Koopa. And in fact, he is. In New Super Mario Bros. Wii and New Super Mario Bros. U, Roy is seen holding a Bill Blaster over his shoulder. He is always shown wearing a pair of red sunglasses, which obscures his eyes in the games, though in The Adventures of Super Mario Bros. 3 and the Super Mario World cartoon, his small eyes are visible through the lenses of his sunglasses. Like Wendy, he originally had a pink shell. However, in New Super Mario Bros. Wii, his shell is a shade of purple. He has a pink head, and is the only Koopaling to have one. His unused sprite for Super Princess Peach bears a green shell, and an orange head. Like most of the Koopalings he has visible fangs in the corners of his mouth; they are bigger than his siblings' fangs.
Mario Kart 8
Roy and all of the other Koopalings made their first appearance as playable characters in Mario Kart 8. He is the only Koopaling to be in the Cruiserwight class.
Super Smash Bros for Wii U and Nintendo 3DS
Roy Koopa appears as a red alternate costume for Bowser Jr. in Super Smash Bros. 4.
In the The Adventures of Super Mario Bros. 3 and Super Mario World cartoons produced by Nintendo and DIC Entertainment, Roy is renamed Bully Koopa and is regarded the oldest of the Koopa Kids.
As his name would imply, Bully constantly pummels and pulls cruel-pranks on friend and foe alike. Out of all the Koopa Kids, Bully seems to have the least amount of screen time in the DIC cartoons, only appearing occasionally. Though, he did have a major role in "Do the Koopa", "Recycled Koopa", "Crimes R Us", and "The Yoshi Shuffle". He is also seen having a supporting roles in "Mush-Rumors" and "The Night Before Cave Christmas". Bully is given a Brooklyn accent in the DiC cartoons, and unlike in the video games, the character wears a spiked collar and has only one spike in the center of his shell.
Roy's name is derived from Roy Orbison.