Shellbug

The Shellbug is a mysterious unique passive creature found in The Elder Scrolls V: Dawnguard. It is located in a secret area in both Forgotten Vale Cave and Sharpslope Cave, both of which are found in Forgotten Vale.

It cannot be killed normally, but can be mined for Shellbug Chitin and a random gem, after which it dies. The chitin can be used to make a Shellbug Helmet. It is a rare insect to find in Skyrim, and can be considered an endangered species.