Unlock a whole slew of Nintendo Characters in SM64! (based off of the severe DKCII glitch found by David Wonn, where you could become Klubba)
Enter Bo-bomb Battlefield and choose the first star. Make your way to the top, where the King Bo-bomb is. Fight him, and pick him up. Throw him slightly over the edge, and jump off to grab him again. This time, though, it will look like he is resting on your legs. Find a nearby wall, and hold him up against it. Now throw him, press ABCupCdownCleftCrightRLZStart, and catch him as he flies back at you. He will explode and you'll be holding a ghost of him that is twice his original size. Jump off of the mountain exactly onto the middle of the flower patch that contains the 1UP. Now, make you way to the first portal on the mountain. Warp to the top. The ghost will be three times the original size. Make it to the very top of the mountain, and you will find the pole that appears when you race Koopa the Quick, but with a large sign that says, "ZOMG[wtd]BBQ! ZOMG[wtd]BBQ!" on it instead of the star. Throw the ghost at the sign. Depending on where you hit the sign, different things may happen. First, your "score" of how close to one of the edges will appear. If you're lucky and managed to hit the very tip of one of the edges (right works better), Mario will go blue, and morph into Klubba. Depending on your score, though, you can get characters ranging from Samus from Metroid to Ralph from Rampage: World Tour. Of course, about 89.314156925% of the time, the game will irrecoverably destroy all of your game data in SM64, and make the cheat impossible to do again. if you get it right the first time though, there is a character select at the start of your game (whee fun!), and you can do the cheat without any problems afterwards.