Monty Mole (1)

First off, you're gonna need Luigi's Thunderhand. Use it to power up the orb right there in the area. This'll make a platform pop outta the ground nearby. Hop onto that platform with a High Jump, and then head into the cave.

Inside, you'll see a sign talking about Simu-Blocks. The goal is to hit both of them at the same time, but they're on different ledges, making it a bit of a puzzle. Here's the trick: have only Mario jump up the ledges to reach the top one. Meanwhile, get Luigi positioned over to the right. Once you've got both brothers directly under a block, press A + B at the exact same time. Nail it, and a bridge will appear right in front of you.

Now, you'll move into the second area. Get ready, because there are two more Simu-Blocks to hit! This time, have Mario jump up the ledges starting from the right side of the area. Luigi should follow along below him. Just like before, line them up under their respective blocks and hit A + B together. Boom! Another bridge will rise up ahead.

Cross that bridge, and you'll reach the final puzzle area. For this one, have both Mario and Luigi jump up the ledges on the right side of the pit. Now, have Mario jump across the pit. This will cause Luigi to fall down to the lower area. From down there, hit both blocks simultaneously. This is the last one, and it'll make the final bridge appear.

Cross the final bridge, and you'll find Monty Mole waiting for you. Talk to him, and he'll give you the Wool Trousers as your reward!