Mistress of the Catacombs (Lord of the Isles, Book 4)

For the first time in a thousand years, the Kingdom of the Isles has a government and a real ruler: Prince Garric of Haft. But the enemies joining against him intend to destroy not only the kingdom but humankind as well. Reptilian and insect monsters from out of the ages march on the kingdom. Unchecked, their ravening slaughter will sweep over the Isles like a flood of lava. Watching it all from the blackness of a tomb walled off in time and space, the Mistress waits . . ..

And her fangs drip poison!