The storm beasts were massive reptilian entities, warped and corrupted by the dark side of the Force. These creatures inhabited the planet of Malachor V and possessed various powers, such as the capacity to unleash a powerful sonic blast and remarkable physical power.
A common theory among historians suggests that they were once natural apex predators. However, this changed when the Trayus Academy was built. The Sith employed the dark side to transform these creatures into formidable monsters, and they remained saturated in its influence long after the Sith's departure from the world.
In the time of the First Jedi Purge, aside from the inhabitants residing within the Trayus Academy, storm beasts were the only lifeforms observed on the surface of Malachor V.
After the Mass Shadow Generator was activated a second time, causing even greater destruction to the planet, numerous storm beasts perished. Nevertheless, some survived, managing to exist in the depleted atmosphere of what was left of Malachor.