Guardians of the Galaxy nearly featured the Badoon, one of the most fearsome warrior races in the Marvel Universe — and here's the concept art (by Goran Bukvic) to prove it. Plus check out more of Bukvic's concept art, covering weapons and and a cool table. Minor spoilers below...
Bukvic seems to have been mostly involved in designing weaponry and gadgets for Guardians — but in the process of working on that, he got to design a bazooka for the Badoon, who would have been the troops working for Ronan in the original version of the story. Alas, the Badoon are owned by Fox as part of the Fantastic Four/X-Men rights, so they were replaced by the Sakaarans from the Planet Hulk storyline.
Check out more of Bukvic's art below, and there's more over at Comic Book Movie.