This specialized dungeon protector is the larger and harder to destroy of the two types that appear in game (the other being the regular dark protector). The fancy dark protector has a larger radius than its smaller sibling: 22 blocks as opposed to 15. Also, it requires a higher level of Engineering Skill to destroy.
This device is always accompanied by at least one guardian brain that can be an adult brain, a large brain, or a dire large brain. It's likely that bat spawning inside dungeons is also related to the presence of a dark protector.
Visually, it differs from the regular dark protector in having a spiky base and two small spikes that protrude from its head.
For more information about dark protectors in general, see the dark protector page.
Level 5 Engineering Skill is required to destroy this protector. You can mine it with a pick, a shovel, or a spade.