Gefarlus Bertoloso was a rare spider that featured in Sanctuary.
Gefarlus Bertoloso was an ancient aquatic species of Abnormals that was believed to be thousands of years old and predated many known civilizations. According to Edward Forsythe, it was believed that the creature originated from Pangea; a supercontinent that was home to many species of rare as well as exotic Abnormals though there was no conclusive proof of the matter. Only a single member of the breed was known and was incredibly old; dating back more than five thousand years ago. This female specimen also possessed a cousin species known as the Macri that served as a psychic link to Gefarlus Bertoloso. Its great powers meant that it was classed as an extinction-level Abnormal and was capable of influencing the planet itself. The power of the creature led to it being worshipped by a Hindu cult known as the Cult of Kali which had existed for five thousand years. Through the Macri, the Cult formed prophets that served as heralds to Kali which was actually the Gefarlus Bertoloso. When the creature influenced the world, the Dutes as they were known informed the Cult and others of the impending disaster thus saving lives. Many of the Abnormal's heralds cautioned it for leniency over the years.
At some point in her early career, Helen Magnus discoveered the specimen and labelled her under the name of Gefarlus Bertoloso though she commonly called it Big Bertha. Whilst she concluded that the creature was incredibly powerful and had the power to harm the world, Magnus's study believed that the Abnormal had a close tie to the ecosystem. In order to prevent it from being abused and to make others feel safe, she reported to the Sanctuary Network that she had destroyed the creature. However, in fact, she relocated Big Bertha and placed her in a contained location at the bottom of the Indian Ocean where she was constantly monitored. Magnus kept the continued existence of Big Bertha a secret to prevent others from finding her and to prevent others out of fear in destroying her as Helen believed that destroying the Abnormal would lead to great ecological damage to the world to which it was linked. Despite this being the case, Edward Forsythe believed Big Bertha to still be alive and went about an exhaustive study of the creature in preparation to one day control her.
By the modern age, however, there was some evidence that indicated Big Bertha was still alive. This discovery by Triad member Emma led to an elaborate plan involving telepaths as well as the forced confinement of Helen Magnus to find a tracking device to the Abnormals cell. However, once Emma arrived, she learnt that it was a trap made by Magnus to catch spies in the Sanctuary Network leading to many believing that the ancient Abnormal was dead. Months later, Magnus herself confessed though that she did not kill the creature and had kept her alive. Whilst the first attempt at Big Bertha failed, Edward Forsythe went about a different path to locate Gefarlus Bertoloso. This involved finding the host of the Macri of the much diminished Cult of Kali in India. Initially, they were successful in finding the host, but he managed to hide the Macri whereupon the cult member died. The spider later bonded with Will Zimmermen leading to him glimpsing at the Kali manifestation of Big Bertha in his mind. However, Forsthye was successful in capturing Zimmermen and forcing the spider out of his body whereupon he bonded with it forcibly. Using his connection to the Abnormal, Forsythe intended to bring about the end of days by coaxing Big Bertha into forming an island in the Indian Ocean as well as creating a number of worldwide disasters. His plans were somewhat thwarted as Zimmermen retained a link to Kali and calmed her but Sanctuary leader Terrence Wexford detonated depth charges in an effort to kill Big Bertha. This led to the giant arachnoid climbing up the newly formed island and creating a devastating tidal wave as vengeance for the attack.
Big Bertha as she was known was a giant marine Abnormal resembling a spider. It lived a life mostly underwater and had the power to influence magnetic fields by resonating the energy from its abdomen. This power made her an extinction-level Abnormal as by simply making contact to the bottom of the ocean, she was capable of finding tectonic plates and resonating her energy. This led to influences of the planet's magnetic field thus causing spikes to electronic equipment and even shift the tectonic plates. Such actions allowed her to cause powerful tidal waves, devastating earth quakes and even form islands. Her power meant that she was easily able to destroy the entire planet if she so desired. Despite this being the case, Gefarlus Bertoloso was not aggressive but quite passive in nature. She retained a psychic link to the hosts of the Macri and appeared to them as a beautiful Indian woman.
Though it could be seen as a simple animal, the creature was quite intelligent and had a sentient mind. It believed itself to be Kali; the Hindu deity and those that the Macri bonded to were called Durga by her. In her own mind, Big Bertha simply desired to live in peace and alone. However, she was also quite dismissive of the effects of her power and believed that it was well within her rights to kill millions. Furthermore, if in pain, she was capable of feeling emotions such as anger and understood the concept of betrayal.