Redmaw was a legendary Thunderjaw and a highly sought after kill by members of the Hunters Lodge in pursuit of the title of Sunhawk. Many hunters met their end while trying to take it down, including Talanah's sponsor, Tarkas, and Ahsis. At some point, this monstrous machine's history was chronicled by Inquiring Jandiniman, Historian-In-Residence at the Hunters Lodge. While he attempted to separate fact from fiction when possible, he admitted that it was difficult to find accurate information.
Given Redmaw's reputation for killing those that set out after it, it became an expression among the Lodge members that if a hunter went missing and never returned, it was the work of the notorious Thunderjaw.
While no conclusive evidence has been provided, it is thought that the destruction of a freehold at the Hands of the Flood and the deaths of nine people in the spring of the 18th year of Sun-King Jiran's reign was Redmaw's first attack. In the late spring of the same year, four hunters set out from Sunstone Rock to further investigate; all of them perished. This was also assumed to be the work of Redmaw.
The first actual sighting of this particular Thunderjaw came in the early summer of the 18th year of Jiran's reign, when a wounded survivor returned and gave it the name for it's ability to bite a man in half. Of six mercenaries, he was the only survivor. While another, larger expedition set out from Meridian in the late summer, none returned and only six bodies (out of eight members total) were found near Blackwing Snag.
The situation escalated in the fall of the same year, when Jiran ordered members of the Hunters Lodge to pursue the monstrous machine. After some delays in obtaining supplies, three Hawks and their Thrushes set out; one pair survived to tell the tale, and they were killed for their failure. After that, experienced members of the Hunters Lodge did not even make plans to take down the Thunderjaw. Novices, on the other hand, eagerly joined in future hunts.
Interest in killing the beast was re-ignited in the 19th year of Jiran's reign when an Oseram trading caravan totaling six members was destroyed near the Spurflints. Almost a year later, three military expeditions were mounted to kill Redmaw, with 34 men in total. Due to attacks by Stalkers, only four made it back, and this again stalled further hunts.
In the first year of the reign of the Sun-King Avad, Redmaw again attacked an Oseram caravan, this time leaving a survivor. The survivor begged Ersa, the captain of the Vanguard, to send an expedition after the monster, but she denied his request. Over the course of the year, three more expeditions were mounted against the machine; all failed. Out of 27 men total, only five survived. During the third year of Avad's reign, Redmaw was again sighted, this time near Thunderhead by Tarkas and Talanah. While Tarkas was mortally wounded, Talanah later testified that his spear was still embedded in the machine's side when it left the area.
Events of Horizon Zero Dawn
In the summer of the third year of Avad's reign, Talanah set out to kill Redmaw in a bid to earn the title of Sunhawk and avenge Tarkas' death, with Aloy following soon after. Ahsis sought to keep the title at all costs, and hired a group of mercenaries to stop the pair. After a failed attempt by Ahsis that left the hunter mortally wounded, Redmaw was finally defeated by the combined forces of Talanah and Aloy, promoting Talanah from Hawk to Sunhawk. Jandiniman described it as "a fight for the ages".
- Redmaw is the only Thunderjaw to be recorded in The Jewel.