Scarab

Scarab(スカラベ) is the spirit of ancient bugs and the guardian ghost of Nakht Pitrah.

About
These bugs were considered sacred by the ancient Egyptians, who thought the sun was moved by one of these insects as if were one of their balls.

Oversouls and Attacks
Nakht can make his oversoul with this nature spirit and his pyramid head, and uses the pyramid power to attract sunlight and recover furyoku. The pyramid can also create a defensive barrier though Nakht couldn't use it to save himself because he was instantly killed.

Anime/Manga Difference
Scarab never appears in the manga or anime. In the anime, Nakht's guardian ghost is a sphinx.