Tandem Sword

The Tandem Sword is a treasure in. It is actually a pair of with a light-blue handle. It is about seven times the length of Captain Olimar, and the handle is three times his height. Olimar mistakes the treasure as a weapon because of its cutting properties.

Collecting the treasure
After defeating the Crystalline Crushblat, climbing down a vine will put you between two iron blocks, with the one on the left being pushed by a Stony Flint Beetle. You should push the block on the right, then wait for the Beetle to push its block all the way to the right. The block will hole up a gap, allowing you access with your Pikmin. It will take all twelve Pikmin you should have at this point to carry the treasure off of it its platform.