Big Mother's History
Billions of years in the past, the dark god Knull created a horde of symbiote dragons from the living abyss and dispatched them to wreak havoc across the cosmos. Manifested from Knull's divine blood, one symbiote dragon was red in color and took to accompanying one of its siblings in their interstellar feast.
Medieval Times
In the sixth century, the two symbiote dragons made their way to Earth and began terrorizing the Danes of Denmark; the black symbiote dragon coming to be known as "Grendel" and the red symbiote dragon as "Grendel's Mother". Claiming a flooded cave hidden behind a waterfall as its lair, the red symbiote dragon was enraged when the Grendel was struck down by the Asgardian storm-god Thor Odinson. Going on a vengeful rampage, it attacked Heorot Hall and killed Aeschere - the chief warrior of King Hrothgar - and several other Danes in retaliation. In retribution, Thor tracked the red symbiote dragon to its lair in a cave hidden behind a waterfall. While it was believed by the evil sorcerer Merlin Demonspawn that Grendel's Mother had been vanquished using Excalibur and sealed away in a floating underground prison, the red symbiote dragon had been electrocuted by Mjolnir in a mid-air battle with Thor, its unravelling body plummeting to the depths of the North Sea.
Following this, Thor's exploits were attributed to the Geatish prince Beowulf and were recorded by Anglo-Saxon poets in an epic entitled Beowulf - although numerous details were falsified.Grendel's Mother was misidentified as an ogress and the mother of the half-dark elf warrior Grendell - who had also purportedly been slain by Beowulf - and his brother; and the poem also erroneously put forth that she had been slain by Beowulf.
At some point, Grendel's Mother reconstituted itself into a quadrupedal draconic form with feminine attributes, purportedly being sealed away in a floating underground prison that slowly made its way from Scandinavia to the west coast of the United States
Modern Age
In the early twenty-first century, Merlin Demonspawn unleashed Grendel's Mother from her prison so that she could wreak havoc on the world, but was incredulous when she transformed from a draconic beast into a feminine humanoid form. Before she could devour anyone, Marlo Chandler convinced her not to listen blindly to Merlin, arguing that he wanted something from her in exchange for her freedom. Confronting Merlin, Grendel's Mother demanded to know what he wanted of her, to which he replied that he desired the goblet belonging to the dragon slain by Beowulf, which he believed was the Holy Grail. Grendel's Mother stated that she remembered the dragon of which Merlin spoke as well as the location of its lair, but refused to take him to it; angry that he thought that she would obey him simply because he had freed her. Their argument was interrupted by the arrival of Captain Marvel, Moondragon, and Al wearing Red Raven's armor. Simply walking away in the chaos, Grendel's Mother quickly becoming enamored with the modern world and encountered booking agent Mordecai Boggs. Intrigued when he offered to make her a star, she signed a five-year contract to become a pro-wrestler under the gimmick of "Big Mother".
However, Big Mother's rage and hatred were eventually rekindled when she learned that Thor was revered as a hero by the humans, and that her and her "son's" defeats had been falsified and glorified into an epic poem.
Fear Itself
When Cul Borson was unleashed, Big Mother participated in a debate among powerful demons, elder gods, eldritch entities, and other dark gods held at the Devil's Advocacy over what should be done about the God of Fear, listening to Mephisto's suggestion that they should do nothing except sit back and enjoy the carnage.
Scream
In the wake of Carnage's attack on New York City and Knull being unleashed, Big Mother established a lair in a shipwreck off the coast of Manhattan and began assembling an army of monstrosities formed from drowned corpses amalgamated with sea-life and reanimated by her living abyss, vowing to set right the lies told about her "son" by those who had written Beowulf.
Drawn to the Scream symbiote and hoping to claim it as a surrogate daughter, she began sending her reanimated monsters after the symbiote's host, Andi Benton. When Scream attempted to take the fight to her, Big Mother separated the Scream symbiote from Andi and left the human girl to drown. The Scream symbiote managed to escape and rebond to Andi, rebuking Big Mother's insistence that they were family. Angered by the Scream symbiote's continued refusal to comply, Big Mother foiled Scream's attempt to escape and ripped the lesser symbiote off its host once again, swallowing Andi whole as she tried to swim to the surface. The Scream symbiote rejected Big Mother again and rebonded to Andi, who as Scream ripped her way out of Big Mother's body.
Frustrated to the point of deciding to just kill Scream, Big Mother chased her to the surface and up the side of an under-construction skyscraper; Scream using a construction crane's cable as a makeshift noose in an attempt to lynch her - though the Scream symbiote noted this wouldn't be enough to kill her. As Big Mother struggled to free herself, she accidentally severed her own head, her last words to Andi being that Knull was coming.
After her apparent death, Big Mother's body was claimed by the F.B.I.'s Anti-Symbiote Task Force.
