The symbiote that later became known as Venom was created by the dark elder god Knull on a desolate, nameless planet; where it saved a group of newborn baby rodentoid aliens by bonding to them and transforming them into apex predators.
After the symbiotes were freed from Knull's control and formed themselves into the Klyntar, most of the symbiote's memories were presumably altered or erased,as it later believed itself to be the 998th generation of a lineage of symbiotes born on the planet Klyntar, hatched from a clutch of eggs in a cavern.