Undead Cyclops is the 2nd of the Four Final Bosses. Undead Cyclops is the reincarnation of the first Cyclops that was defeated earlier in the Game. Visually, he is different than the original Cyclops. Patches of skin appear to have gone missing and his eye has been replaced with magma.
Undead Cyclops's attacks consist of swiping a large coffin at the Player, shooting fireballs through his eye, and opening up the coffin, unleashing the Undead Groom. Undead Cyclops hops around on the coffin in attempt to crush the Player, while Undead Groom rushes into the Player. During this attack, both Undead Cyclops and Undead Groom are Invincible. In time, Undead Cyclops will call Undead Groom back to his coffin and repeat the series of his previous Attacks again. Remember, you can block the fire balls by pressing LT/L2, which brings out your shield.
Undead Cyclops is considerably easier than the original Cyclops, due to the fact that you can effectively block his attacks (except for the Groom). When Undead Cyclops runs towards you, use your shield to block his coffin. If he successfully hits you, you will take significant damage, especially on Insane Mode, so try to master the timing. Immediately after, use some form of attack (such as your splash) and spam it as much as possible until his next swipe. However, make sure to stop at the correct time as he might hit you while you are performing a move. Repeat this sequence until his next attack.
Once he attacks you a few more times, he'll run away and launch fireballs at you. This, like his previous attack, can be easily blocked. Since he is a distance away, you can use your Bow or Magic to tack on some extra damage. A skilled player will be able to fire 1-2 projectiles in between each fireball, lowering his health somewhat. The fireballs themselves are not that powerful, dealing a meager 5 damage (unless you are in melee range of him), even on Insane Mode, so getting hit by them shouldn't be too detrimental.
After his fireballs, Undead Cyclops will release the Undead Groom, who will charge in your direction dealing a considerable amount of damage, albeit not changing direction until the end of the charge. Undead Cyclops will attempt to crush the Player by hopping around the battlefield. During this attack, both Undead Cyclops and Undead Groom are invulnerable to any form of attack.
Due to the fact that Undead Groom travels in a linear path and will not change direction until the end of the charge, it shouldn't be too hard to avoid him, though his high speed can catch low-agility players off-guard. Staying in the air makes it impossible for Undead Groom to hurt you, so by using some form of levitation you can avoid taking damage with ease, as Undead Cyclops isn't too fast on his coffin.
Another simple way to avoid the Undead Groom is to take a hit from the Undead Cyclops' hopping attack and hide in the ground until the Groom returns to his coffin. This deals negligible damage to the player, and while underground the player is invulnerable to damage, making it impossible for both Undead Cyclops and Undead Groom to deal damage. Once he hops 20 times on his coffin, he'll call Undead Groom back to his coffin and repeat the same series of attacks again.
After killing Undead Cyclops, he will drop the coffin and both him and the Undead Groom will fade away. A Boss Chest will fall down from the sky and a ghost of the Conehead Groom and Cyclops will levitate upward, off-screen. Continuing will show another Large Purple Crystal which, once destroyed will unlock the Next Boss.
- The theme "The Cyclops' Revenge" plays in the original Cyclops battle from the ending of the level "Cyclops' Fortress" as well as in the Undead Cyclops Battle.
- The Undead Cyclops is also referred to as the Vengeful Cyclops.
- In the Background you see the Dragon and Sock Puppet you killed earlier in the Game.
- You can also see the Eye Gate from the Cave Level from back in the Game.
- There is a fossilized Fire Demon in a crystal in the Foreground. This is proof that Fire Demons aren't humans wearing masks.
- At the end of the Game where you are about to kiss the Orange Princess (Tricky the Clown), you can see some of the Enemies and Bosses you fought earlier in the Game, including the Groom's ghost playing his Harp behind the Keyboard.
- If you look around where his eye used to be, you will see what looks like water stains on his skull. This possibly indicates how much he cared for the Groom by (almost literally) crying his eye out.
- While hopping on the groom's coffin, the Undead Cyclops will jump exactly twenty times (per cycle of attacks). Since each of these jumps visibly shakes the whole room, it is easy to tell when you should prepare to start damaging the Undead Cyclops again.
- There is a weapon in the Cyclops' room. Near the arch leading to the next crystal, there is an X formed of bones, dig here and you will uncover the Wooden Mace.
- You can avoid the Undead Groom's attacks by getting crushed by the coffin. However, staying underground too long will cause the Undead Cyclops to go off-screen until he is done hopping on the coffin.