Molgera

This gargantuan Lanmolas-like creature lives in the depths of the Wind Temple, waiting for its prey. This monster is directly responsible for the death of the Wind Sage. It must be defeated in order for Makar to be placed in as the new sage of the Wind, and for the Master Sword to return to full power.

Strategy
When Molgera emerges from the sand, be careful not to get too close to it's gaping mouth. He will devour you and cause severe damage before spitting you back out. Get close enough, however, and use L-Target to grab his tongue with your Hookshot. Now that it is near you, use the Master Sword and slash away. This is what causes damage to Molgera.

One of it's other attacks is to send out three baby Molgeras to annoy you. Use the Hookshot to latch onto them, pull them to your side, and slash them. they will reward you with hearts. In the meantime, watch out for Molgera as it emerges from the sand and flies through the air, attempting to crush you when it dives back in. Watch that you don't get sucked into the bottom of its sand pits either. Keep hooking and slashing his tongue until he is done. He will fly into the air and explode in a shower of sand, revealing the Triforce crest with the blue light.

Your rewards from this fight are a Heart Container and a fully powered Master Sword.

[edit] Trivia Molgeras name may be a pun on the name of a robot monster seen in The Mysterians, Moguera.