In the comics, Drax is a former human who was transformed into a being of extreme power to avenge the death of his family at the hands of malevolent cosmic God Thanos, who is obsessed with destroying all life to bring him close to Death, a female figure of which he is in love with.
Thanos was introduced at the end of Marvel Studios' "The Avengers" as a way to open the door towards telling more stories in the intergalactic, cosmic realm of their cinematic universe. Guardians of the Galaxy will continue that direction.
Batista has done a number of film and TV roles since leaving WWE, including most recently the "Man with the Iron Fists."
In an interview with the PWInsider.com Elite section a year ago, Bautista did not rule out an eventual WWE return, but noted that he wasn't a fan of the current PG direction. However, he did note that when he did return, it would be for one final full-time run, as opposed to coming in to doing a big Wrestlemania match or another cameo, which he didn't feel was right for him or the audience.
And yes old school comic fans, Rocket Racoon is slated for the feature film. 'Nuff said!