Tomb Serpent

Scarce had he finish'd, when, with speckled pride,
A serpent from the tomb began to glide;
His hugy bulk on sev'n high volumes roll'd;
Blue was his breadth of back, but streak'd with scaly gold:
Thus riding on his curls, he seem'd to pass
A rolling fire along, and singe the grass.
More various colors thro' his body run,
Than Iris when her bow imbibes the sun.
Betwixt the rising altars, and around,
The sacred monster shot along the ground;
With harmless play amidst the bowls he pass'd,
And with his lolling tongue assay'd the taste:
Thus fed with holy food, the wondrous guest
Within the hollow tomb retir'd to rest.

- Virgil, Aeneid

like this but bigger

 The Tomb Serpent resembles an enormous snake, covered in blue scales streaked with gold. When the serpent moves, it creates flames from the friction of its body against the ground. If disturbed or attacked, its thrashings can quickly build up a large blaze. As the name implies, the Tomb Serpent is usually found in the tombs of great heroes, and many believe that it is sent there by the gods to protect the heroes' legacy.

Offering holy sacrifices of food and wine outside the tomb will lure the Tomb Serpent from its lair and distract it for a short period of time. However, one must be careful to learn the religious traditions associated with the tomb; if the wrong rituals are observed, the Tomb Serpent will be thrown into a vengeful rage.