In ‘Venom’ (2018) #4, the dark Elder god Knull in Knowhere tells Eddie Brock about the origin of the Venom symbiote, the Klyntar.
The story begins with the Elder god Knull “in the beginning” being invaded in his dimension by the Celestials.1 Seeing it as a war between light and darkness, Knull summons a sword out of the Abyss and decapitates a Celestial.
Then, using its remains, he forges the necrosword, the beginning of the symbiote. He sets out to attack the night and is then repelled onto a desolate, abandoned planet. Then, Knull creates the symbiote on the planet by bonding his abyss with lesser creatures. Eventually, Knull raises an army to slay gods across the galaxy until they reach Earth.
The Grendel, which is a dragon sent by Knull to slay worlds, reach Earth and are slayed by Thor’s lightning bolt. The bond between Knull and his army is broken across the galaxy and the symbiotes become infected by “venom”.1 They become the Klyntar and rise up against Knull who is consumed by the darkness.
In ‘Venom: Dark Origin #4’, the symbiote tells Eddie Brock his origin story. He remembers 60,000 light-years away and being born on the nameless desolate planet. There, Venom protects a rodentoid alien by transforming it into an apex predator.