Origan of the corrupt symbiotes like Venom

I while back we made a post about venom, a villain who faces Spiderman from time to time. Now I wanted to share where the symbiotes came from.

It all starts with an even more dangerous villian Thanos, at a time he visited a planet in the Andromeda Galaxy inhabited with a peaceful race of symbiotes called the Klyntar. The alien symbiotes lived in symbiosis with the other life forms on their home planet. They endeavored to create an intergalactic peacekeeping society by using the symbiosis they need to subsist in order to transform worthy hosts into the ultimate noble warriors, the Agents of the Cosmos. However, to achieve this perfect symbiosis, the host must have a perfect blend of moral and physical ideals. If not, the resulting symbiosis would corrupt both the Klyntar and its host. Symbiotes are fully aware and sentient creatures, but when corrupted they are vicious and wild, compelling their hosts to violence and corrupting them.

Now to continue the story,
Thanos saw how the host became stronger and he wanted to use them as a weapon. So he abducted the Klyntar, vaporized there planet and took them to the barrent Planet X where he experimented on them. In an attempt to control them, he removed there freewill and therefore corrupted them. He experimented on his daughter Gamora, but when he realized the symbiotes where just to hard to control. He removed the symbiote back from Gamora and left the planet for what it was.

Later on the planet got a visit from the Guardians of the Galaxy, since Planet X was also the original home planet of Groot. They soon discovered that the planet was infested with these corrupte symbiots and decided to destroy the planet so no one else could get infested with these symbiotes. Now by doing this some of the symbiotes where able to hitch a ride with some of the rumbel of the planet which scattered trough the universe, ....


Now you now marvel, different realities/universes, ...

Depending on what you are reading/watching there can be 2 varieties of the symbiotes, the ones described above, but also a version that is engineered from the genetic material of Spider-Man. But despite being completely unrelated to each other they are seemingly functionally identical.

Anyway the most famous "corrupt Klyntars" or "Genetically engineered" symbiotes are  Venom, Carnage, Toxin, and Zzx