Timmorn hatched around the time Aquaman was a boy being raised by his dolphin mother Porm , who urged him to stay away from him. However the young Aquaman commanded her that he could choose his own friends and the two played together for many years. However eventually they departed as they grew up and they would not meet again until much later in their lives. Eventually Timmorn was driven by Triton to attack a local resort, where he battled Sentinel and the Flash with two veteran heroes preparing to kill the monster until Aquaman saved him with an attack on Sentinel before paying for the damaged which had been caused and allowing the monster to return to the sea.

Timmorn then returns shortly later, where he battles The Flash as Sentinel stays with a man who had a heart attack caused by his attack. Aquaman then returns and knocks the monster out, with Sentinel passing the news about the man's passing to Aquaman and telling him Timmorn must die. Aquaman then agrees to do it and rides his friend out to see where Timmorn tells him the idea just suddenly appeared in his head, Aquaman then shows his harpoon hand through his skull into his brain killing him childhood friend. Timmorn's son then comes to his father's body, where Triton appears offering him the chance to gain revenge to the young monster taking him to Nuliajuk who mutates him.