Reznor ("Buibui", spelled ブイブイ in Japanese and 부이부이 in Korean) is a gray-colored, fire-breathing triceratops that appears as a fortress boss in the Super Mario series. It also appears in Super Mario Adventures and the Japanese manga, Super Mario-Kun. Interestingly, they always battle as a quartet (except for World 1-Tower in New Super Mario Bros. 2) and can be found standing on top of platforms connected to a giant wooden wheel. The platforms are similar (in terms of the concept) to the rotating magenta platforms first found in World 1-1: Make Eggs, Throw Eggs of Yoshi's Island for the SNES and Game Boy Advance.
Reznor made its debut as the boss of Vanilla Fortress in Super Mario World. Additionally, this fortress is the only level in the entire Mario series where Mario or Luigi have to swim through the entire level before reaching the boss.
Their greatest strength lies in their number, while their biggest weakness lies in the fact that they are standing fixed onto their own platforms. Mario or Luigi need to hit the platform only once from underneath to knock a Reznor into the lava pit. Alternatively, the hero can shoot several fire balls directly to knock it down. Once two of them fall into the lava pit, things begin to change. The remaining two Reznor jump from platform to platform and spit out more fireballs during the process. The floor underneath starts to quickly break apart, and the hero's best strategy is to jump onto an empty platform. He can jump from platform to platform and use either strategy to knock the remaining Reznor down.
New Super Mario Bros. 2 introduced several changes. Among them were:
- Reznor are situated on top of yellow, rectangular-shaped coin blocks instead of on simple grey platforms.
- The wooden wheel now features a giant, flat-head screw in the center of the wheel instead of the inscription "REZNOR".
- They have been moved to the tower levels, with each battle being more difficult than the previous one.
- Reznor layouts are now different. The first tower level, World 1-Tower, features a single, four-block wheel with two Reznor on it. World 2-Tower and World 3-Tower add two more Reznor on the wheel, four a total of four. World 4-Tower features two, four-block wheels with two Reznor each. Additionally, one bridge is to the left of the leftmost wheel, while another is to the right of the rightmost wheel. World 5-Tower has the same layout as the previous tower, except that a single bridge is located between the two wheels. Finally, World 6-Tower has a giant, eight-block wheel with four Reznor riding on it.
- Reznor was named after Trent Reznor (of "Nine Inch Nails" fame).
- In both the Japanese and Korean languages, "buibui" means "to make a peace sign".
- The plural of "Reznor" is officially called "Reznor", just like in deer, moose, sheep, and fish. (This has been confirmed in two different ways. First, in the fortress levels of Super Mario World, you can see the inscription "REZNOR" on the rotating wheel. Second, after Bowser is defeated and the baby Yoshi eggs hatch during the credits, the screen eventually shows a picture of the quartet with the word "REZNOR" in the center of the screen.)