The Cyclops is a mythical monster having only one eye and is the boss of the Kastulle Ruins Lower Floor. It is red in appearance, and very large.
The Cyclops has numerous attacks. One of them is an attack where he throws a rock that travels a short distance and damages those not directly in front of him, behind him, in one of the two holes in the stage, or on one of the three platforms on the stage (the left and right ones are only safe once the rock has landed on the ground). He can also swing his arm and knock the players directly in front of him to the far side of the room. Another attack of his is where he rams players with his shoulder. The Cyclops has a Jump attack, where he slams the ground with both fists, and a Danger move, where he does the ground pound attack, and various Blast Bombs are created on the top platform and side of the map.
In the Cyclops' chamber, there are numerous gas clouds that spawn around the top and bottom sections of the map, where the Cyclops cannot reach. Using the Gas Mask can negate it's damage.