You've defeated all the monsters, but the Freezrex has a guardian hewn from pure frozen ocean water, a titanic creature that cannot be felled. Even should you all defeat it, it will be back someday.
The Snowman is the second to last act of this raid. He is a large single target water monster.
Raid Duration: 12 Hours
Since the Snowman is a single target, Using 3 Leaf combos is the most effective way to do damage. Leaf monsters excel in this entire raid as all of the monsters are of Water type. Fire is weak to Water type, so doing a 3 Fire combo is the least useful of the Elements combos.