The Collective Mind From Venom: Let There Be Carnage Explained
Spoilers for the mid-credtis scene of "Venom: Let There Be Carnage."
In the mind-twisting and multiverse-hinting mid-credits sequence of "Venom: Let There Be Carnage," Venom hints at a power his race has that could break poor Eddie Brock's (Tom Hardy) brain. Venom tells Eddie that, thanks to his symbiote nature, he shares a collective consciousness with all the other gooey aliens of his kind. The Symbiote has been keeping a lot of this knowledge from Eddie because humans aren't great at comprehending the infinite. It tends to make them go bonkers as it did with the Master in "Doctor Who."
Venom says he will give Eddie just a little taste of this infinite knowledge when the universe seems to shift into something different. It's brighter and more Disney-fied than the Venom-verse we know.
But this isn't the Collective Mind's doing. Per Venom, someone else (maybe Doctor Strange) caused Eddie and Venom to shunt off into the wrong 'verse. So then, what's the deal with the Collective Mind?
The Symbiotes share a mind
To understand the collective mind, one needs a brief background of Symbiotes themselves. They were created by the dark god Knull, the first of which appeared as a sword that he used to sever the head of a Celestial. Knull then created Symbiotes out of pure darkness to defeat life and light across the cosmos. Each and every being was connected to Knull, but eventually, one Symbiote became infected with ideas of nobility and goodness. As explained in "Venom" Vol. 4 #4," the Symbiotes imprisoned Knull after rebelling against their creator, but kept the shared consciousness — now without a ruling mind.
This being comics continuity, we can't stop at one rebellion, as "Guardians of the Galaxy" #23 explains. Some bloodthirsty Symbiotes rebelled against the honorable ones and started their own quest to conquer/mesh with the world, Borg style. The Symbiote that would become Venom was an outcast of this group because he didn't want to kill his host bodies. As Venom explains in the first movie, he is a loser on his home planet because he cares too much. Venom loves love, which is why he protected Eddie from the Collective Mind in the first place.