The Guardians of the Galaxy constantly travel through space visiting strange planets and having unique adventures. For a group that’s traveled so far, it was inevitable that they would eventually encounter one of the most dangerous alien species in the Marvel Universe; the symbiote. What’s surprising, however, is how easily the aliens took down a squad of mercenaries known galaxy-wide.
In Guardians of the Galaxy Season 1, Episode 8, the Guardians are attacked by symbiotes that are seemingly more evolved than the ones familiar to Marvel fans. They aren’t as susceptible to heat or flame, and although they still seek hosts, they don’t seem to require one to manifest a physical body. This made them a bit trickier to deal with than the regular symbiotes.
A search for the Cosmic Seed takes the Guardians to the caverns of a strange unnamed planet. After Groot inadvertently trips an alarm, the Guardians find themselves forced into a shadowy chamber with no apparent exit. This is where they first encounter the symbiotes and attempt to defend themselves from the alien parasites. In the battle that ensues, they discover lasers and flamethrowers don’t have a long term effect on the symbiotes and decide to make a hasty exit. In true Guardian fashion, they blast 80s music at a high enough frequency to keep the symbiotes at bay. Unfortunately, the frequency also caused Groot intense pain. They get to the planet’s surface otherwise unharmed, but not before Drax the Destroyer chops off one of Groot’s arms that had a symbiote stubbornly clinging to it.
A minor hiccup involving an ambush by Yondu and the Ravagers on the surface give the symbiotes enough time to catch up, but Rocket defeats them easily by trapping them in his pocket dimension. Yondu’s ship is damaged when the symbiotes show up, giving the Guardians a chance to escape him on the Milano -- unaware that they have a symbiote stowaway.
When the team splits off on the ship to take care of their various chores, the symbiote chooses Groot as its host. Sensing lingering resentment towards Rocket from his earlier rudeness when asking him to do his chores, the symbiote bonds with Groot and amplifies those negative feelings.
Symbiote Groot confronts Rocket with the intention of podding him too. When Rocket is cornered, Symbi-Groot plays back several of the hurtful things Rocket said to him. Rocket freezes when he hears his words about not caring that Groot was the last of his kind and almost ends up podded, but Star-Lord intervenes. The duo evades Symbi-Groot and hides so they can come up with a plan to make a sonic weapon even more powerful than the previous one.
Symbi-Groot attacks again, this time declaring that they will no longer be a servant or the last of their kind and revealing their plan to spread throughout the galaxy using the power of the cosmic seed. Rocket fires the weapon at him and it does take care of the symbiote but turns Groot to dust in the process.
The Guardians come up with a plan to restore Groot. Rocket enters the pocket dimension to try and steal back the arm Drax cut off from the symbiote. If planted, Groot would be able to grow back.
The plan seems to be going well until Yondu arrives and takes Quill prisoner aboard his now repaired ship. Unaware of what it contains, he opens the portal, freeing not only Rocket Raccoon but all the symbiotes trapped inside. His ship is quickly infested and the Guardians slip back to the Milano amidst the chaos with Groot’s arm fully recovered.
Aboard the ship, Rocket apologizes for continually belittling Groot and offers to pick up some of the slack while Groot grows to full health. Rocket realizes that the symbiote was able to attach to Groot's resentment, so hopefully, Rocket will try to be a better friend and teammate.