He came to Gielinor sometime during the Second Age. During this time, he rode the dragon Shakorexis, also known as the King Black Dragon. Sometime during his service as a Dragon Rider, he had a romantic relationship with Morvannon, resulting in an egg. Morvannon was eventually killed by hellhounds led by the Twin Furies, though neither Hannibus and the Furies were aware of the egg. The egg would later be tended by Morvannon's mount Gorvek and would be named Vindicta. After Zamorak's ascension and subsequent disappearance after "killing" Zaros, both sides labeled the Dragon Riders as traitors and hunted them down. Hannibus had avoided his pursuers and resided in the cave that Zaros brought them through with his mount. Hannibus desired to return to Iaia by any means, but was unable to do so.
After the conflict ended, Enakhra started to hunt him down so she could deliver him as a present to Zamorak. Not wanting to endanger Shakorexis, Hannibus left him and searched for another hiding spot. Although he was eventually captured, Enakhra was unable to bring him to Zamorak. Eventually Hannibus was found by Robert the Strong and was brought to his library in Burthorpe for further study. Robert searched for a way to reanimate Hannibus but was unable to before he died.
In the Sixth Age, Mr. Mordaut, seeking more information about the origin of dragons, asked an adventurer to find Robert's library and talk to Hannibus. The adventurer reanimated Hannibus and convinced him that he should go back to his homeworld. Hannibus was interested with the Dragonkin and traveled around Gielinor to speak with several dragons, including the Queen Black Dragon and several mysterious statues. While they did not provide a clear answer, Hannibus eventually realized that his former mount would be able to help him.
With the aid of Hannibus' former mount, the King Black Dragon, they track down Therragorn, a white dragon who has the ability to travel between worlds. Unfortunately, while attempting to fly back to Iaia, an unknown fireball shot Therragorn down, badly wounding Hannibus. When the adventurer woke up, Kerapac extorted them into helping him by stating that he would not save Hannibus if they did not comply. The adventurer complied and helped Kerapac, who upheld his end of the deal by healing Hannibus.
Kerapac told Hannibus that he may have the capability to fix the Ilujanka's fertility problem, but it may take many decades and that it was not guaranteed. Kerapac promised, however, that Hannibus would be kept in stasis.
While thinking this over, Therragorn returned, having flown to Iaia and brought back one of Hannibus's descendants, Sharrigan. Sharrigan tried to convince Hannibus to come back to Iaia where the Ilujanka have accepted their fate and he can die with his kind. Hannibus asked for the adventurer's help in choosing, with their choice deciding whether he went with Kerapac or Sharrigan.
- The dragon rider gloves and dragon rider boots that the King Black Dragon drops belonged to him.
- In addition to Hannibus Hunted, he also wrote Last Riders in which he chronicles how he came to Gielinor and how he became the last Ilujanka left.
- ^ Hannibus, "Hannibus Hunted", RuneScape. "The witch Enakhra is still hunting me... It is worse knowing that she has taken it upon herself to collect trophies for Zamorak, in the form of petrified foes."
- ^ Mr. Mordaut, "One of a Kind", RuneScape. "I have been researching Enakhra's exploits and there are references to such a statue as tribute for Zamorak, but she was never able to deliver it."
- ^ Mr. Mordaut, "One of a Kind", RuneScape. "I found documents that speak of Robert the Strong finding a strange, lifelike statue of an unknown species."
- ^ Kerapac, "One of a Kind", RuneScape. "If you submit yourself to my study, then I believe there is a slim chance - within a few decades - that I may be able to provide a cure."
- ^ Kerapac, "One of a Kind", RuneScape. "I will store you in stasis, so the passing of time will mean nothing to you."
- ^ Sharrigan, "One of a Kind", RuneScape. "It is time you were with us - your people - in our final days... The Ilujanka have embraced our destiny, we are ready for the next life, great grandfather."