Another enemy battle is here, this time against the Brolder. Relatively simple is the Brolder, as it really does nothing but roll around. If you touch it normally, you will take damage, but you can jump on top of it, like so many other enemies. However, simply jumping on top of it won’t defeat the Brolder, as it makes its eyes and arms disappear.
What you need to do in order to get rid of the Brolder for good is once it looks like a normal boulder, run up to it and grab it with the Y button. While carrying it, make sure to keep an eye on it shaking, which means it will revert to normal, so just quickly toss it before that happens. Toss the Brolder into the lava and you will defeat it for good. After getting rid of the first Brolder, three more will spawn, so do the same thing to them to earn a Green Star.