Cardinal will find the Key Sword and give it to you. You must then head back to the Animal Ark to hit the lock with the Key Sword in any way you see fit. The lock will break off and allow the door to open, bringing you to a dark room with Beholder in it.
- The Beholder is a reference to the "Beholder" from Dungeons & Dragons, having similar appearance and properties.
- You can use the Horn or Boomerang to open the door while you are holding the Key Sword.
- The Beholder and Black Morning Star or Unicorn Horn can be combined to have a +8 Magic bonus. The highest amount achievable in the Original versions of Castle Crashers.
- The Beholder and Unicorn Horn can be combined to have a +10 Magic bonus. The highest amount achievable in the Remastered versions of Castle Crashers.
- The Beholder, combined with the NG Golden Sword, can achieve the highest possible Elemental Infusion damage output in the entire game in the Remastered versions of Castle Crashers if using one of the 23 Playable Characters with the Armor Pierce Elemental Infusion, at max Strength, max Magic, and at Level 90.
- This damage output varies on all enemies, but the highest possible damage against certain enemies is 238.
- The Beholder, Zebra, and Cardinal are the only Animal Orbs in the entire game to provide a Magic bonus.