The Dread Guardian is a mob that spawns inside the Dread Castle. The Dread Guardians were sent to protect the Ancient Jewel by the Dreadlord. Dread Guardians will naturally spawn in place of Haven Guardians after killing Helvius. They can also be summoned by Helvius and Herobrine during bossfight.
They cannot despawn and have a base health of 50 (25 hearts). When summoned by Helvius, they have increased movement speed.
The Dread Guardian drops Guardian's Flesh with a 1/2 (50%) chance.