For this you need to destroy a statue of Axel which can be found as a decorative item in a map. There are two ways of finding these, both being found in the item world. The first way is found in a mystery room where you can find Axel. These rooms are very rare, but at least every mystery room you have a chance. The second, easier way is to get to the higher floors in an item room. The statues tend to pop up more frequently in floors 80+. As long as you keep an eye out while going for the other trophies, you should find one eventually.