Super Mario Bros. X Forums

I don't know if this has been discovered yet, but anyway. To do this glitch you must be in the Key Coin section of Super Block Land. (World Star - 5)

Firstly you MUST leave the second Key Coin (the one hovering over the pit of Chargin' Chucks) till last. You need to get the Chargin' Chucks to chase you till they are directly underneath the Key Coin. Hop up on to the ledge beside them and grab the second Key Coin. (Remember this will only work if you have left this coin till last to collect.) The player should be on top of the Chargin' Chuck when the Key Coin is collected and the unlocking of the warp Box plays. When the cutscene ends and gameplay resumes, you should be standing on the Chargin' Chuck's head and he will try to chase you, but being on his head he will just keep running. (This is similar to having a Kamikaze Koopa or Bully attached to a platform in SMBX.) DO NOT MOVE around. If you do, the glitch will end and you will stomp the Chargin' Chuck.

It is relatively simple to do so have fun!

I'll definitely try this out once I get home.

Small update, it may not be as easy as I thought. Though I managed to replicate this once more after discovering it, it seems to no longer work and the Chargin' Chuck will be stomped no matter what. Maybe I just managed to get it exactly twice, I'm not sure. It is easier to do with Peach and her float ability so you can line up a Chargin' Chuck underneath the Key Coin. I did it both times with her, but the other characters I've had no luck with.