Grendel

The symbiote dragon that later became known as the Grendel was created billions of years ago by Knull, alongside a crimson symbiote dragon manifested from Knull's blood. Sent out into the cosmos, the two symbiote dragons rampaged across the cosmos for billions of years, slaughtering pantheons of gods and driving the inhabitants of countless civilizations insane before devouring them.

In the sixth century CE, the two symbiote dragons arrived on Earth and established a lair in a cave hidden behind a waterfall in Denmark. They embarked on a campaign of slaughter to subjugate the planet, razing entire cities to the ground and ravenously devouring any wildlife and humans they came across. At some point following their arrival on Earth, a cannibalistic cult formed and began worshiping the symbiote dragons, erecting grotesque monuments in reverence of them.

Mistaken for the monstrous dark elf called Grendel, the black symbiote dragon - which was being remote-piloted by Knull - began laying siege to Heorot Hall. Attacked by the Asgardian thunder god Thor Odinson, the Grendel attempted to kill him but was struck by Thor's divine lightning and trapped inside a glacier; forming the basis of the legend of Beowulf slaying a dragon.

Old Norse carvings depicting this battle were made by the symbiote-worshiping cult and reveal that pieces of the Grendel's living abyss fell to earth after its defeat and bonded to human hosts, bestowing the cult with knowledge of Knull and the symbiotes.

In 1965, the Grendel's frozen body was discovered by S.H.I.E.L.D., who excavated it and extracted samples of its living abyss to study. Upon determining that the living abyss could transform living beings into predatory monsters, S.H.I.E.L.D. - under direction from the US government to create a replacement for Captain America - established the Sym-Soldier Program, a super-soldier program headed by Nick Fury.

Upon realizing the Grendel was still alive, S.H.I.E.L.D. immediately began searching for a way to kill it, subjecting it to torturous experiments. However, they were unsuccessful and these efforts only sent its enraged offshoots on a killing spree in Vietnam. After its offshoots were subdued, the Sym-Soldier Program was deemed a failure and shut down, with the Grendel being placed into storage in a remote S.H.I.E.L.D. facility alongside them.

It has escaped.

Symbiote Physiology: As a symbiote-dragon, the Grendel symbiote possessed deific powers owing to it having been directly created by Knull, making it vastly more powerful than lesser symbiotes.

Flight: It was capable of interstellar flight, enabling it to annihilate entire civilizations across the universe. Superhuman Strength Superhuman Stamina Superhuman Durability Superhuman Speed, Agility, and Reflexes Accelerated Healing Factor Constituent-Matter Manipulation: Like other symbiotes, Grendel is capable of manifesting tendrils from its biomass, using them to attack prey. Offshoot Generation: Its constituent living abyss is capable of being separated into individual symbiotes that can be bonded to hosts. The Grendel symbiote and its offshoots are also capable of reanimating corpses, which they have done to both Cletus Kasady and Emil Gregg. Immortality: Grendel has survived for billions of years.

Weaknesses Electricity: It is particularly vulnerable to high voltages of electricity. Sonic and Heat: Like most symbiotes, the Grendel was vulnerable to heat and sound, though to a much lesser degree than most symbiotes. Grendel was able to withstand missiles fired by the army.

Weapons Grendel uses its fanged jaws, talons, wings, and tendrils as weapons. Transportation Due to having manifesting a winged draconic shape, the Grendel and its ilk are capable of interstellar flight at hypersonic speeds.

With the apparent sole exception of Big Mother, Symbiote-dragons possess no individual consciousness and act based on Knull's overwhelming lust for destruction and bloodshed. The symbiotes they spawn can develop individual personalities, but most are subservient to and worship Knull.