Source: Rise of the Runelords Anniversary Edition, pg(s). 406
Black Magga arrived soon after the Storval Deep was created by Runelord Karzoug in -5758 AR and started bringing terror and misery to Thassilonian citizens dwelling nearby. For the rest of the Age of Legend, Karzoug never bothered to take any action against Black Magga, leading to rumours that he bargained with Lamashtu to place Black Magga within the Storval Deep.
Black Magga seeks to tear down civilisation, spread fear of monsters and the wilds, and command Lamashtu's servants in their depraved, bloody acts. It is said that Lamashtu speaks to Black Magga directly, and many viewed the monster's words as nothing less than Lamashtu's commands.
Black Magga is biologically immortal, and has spent most of her 10,000 years in Varisia in hibernation. She could slumber for a millennium or more, punctuated by decades-long periods of activity. The more time she spends slumbering, the weaker Black Magga becomes.
The people who make a living around the Storval Deep have long told tales about Black Magga, and hold a few common (but wrong) beliefs about her: many who have seen Black Magga and lived can never speak of their experiences, Black Magga is older than many deities and immune to all divine magic, or her sightings are the omen of devastating storms.
- James Jacobs et al. (2012). Appendix Six: Bestiary. Rise of the Runelords Anniversary Edition, p. 406–407. Paizo Publishing, LLC. ISBN 978-1-60125-436-8
- Greg A. Vaughan. (2019). Rise of New Thassilon. Rise of New Thassilon, p. 12. Paizo Inc. ISBN 978-1-64078-106-1
- Amber E. Scott and Mark Seifter. (2017). Aquatic Adventures, p. 40. Paizo Inc. ISBN 978-1-60125-944-8