Guardians of the Galaxy 2 has a completed script

He took to social media last night to prove it, posting images of the finished cover on Instagram and Facebook, with the words: "So this is what happens when you take your brain between your hands and wring out its every last juice. Being sent out now."

Whatever you're thinking Gunn might have in store for Guardians 2, think big. Earlier this year, Gunn shared the reaction he first got from his Marvel bosses: "I went in and I sat down with those guys and I’m like, ‘Okay, here’s what I think the sequel should be.’ And they were like, ‘Oh, whoa. That’s risky, but okay.’"

Sounds exciting, right?

And that's not even all the Guardian of the Galaxy news we were treated to last night. Gunn also revealed on Twitter that he is "almost totally done" casting the sequel, adding on his official Facebook page that "Awesome Mix Vol. 2 is already finished - all the songs are in the script."

Chris Pratt, Zoe Saldana, Bradley Cooper, Vin Diesel and Dave Bautista will all be reprising their roles as Peter Quinn, Gamora, Rocket, Groot and Drax, while Karen Gillian is set to return as Nebula.

Guardians of the Galaxy 2 is tipped for release in May 2017