The brontolith was a very large, but peacefully docile creature. A herbivore, brontoliths were born to endure. With no natural weapons other than sheer size and strength, they mostly relied on their armored skin as protection from predators. Open wounds were a common denominator throughout their existence, and viruses, bacteria, and more exotic lifeforms often made their way into the brontoliths' bloodstreams. None of these harmful organisms managed to cause any damage, however. The brontolith’s immune cells latched on to anything foreign and either destroyed or assimilated it.
That said, the brontoliths couldn't escape assimilation by the Zerg Swarm, where they were mutated into the ultralisk. The brontoliths' genetic code was dissected, rebuilt and repurposed multiple times. Each phase of the process served to eliminate less desirable traits, as well as augment the creature’s ability to withstand severe punishment. The ultralisk now bears little resemblance to its progenitor.
- ↑ 1.0 1.1 1.2 Underwood, Peter, Bill Roper, Chris Metzen and Jeffrey Vaughn. StarCraft (Manual). Irvine, Calif.: Blizzard Entertainment, 1998.
- ↑ 2.0 2.1 Irvine, Alex. "“Great One”." (April 11, 2013). Blizzard Entertainment. StarCraft Lore: Great One Accessed 2013-04-11.
- ↑ 3.0 3.1 2015-01-16, Ultralisk Science. Blizzard Entertainment, accessed on 2014-01-20