Sharlto Copley
Sharlto Copley plays the protagonist of the film, Wilkus Van De Merwe. Wilkus in a kind, polite man who works for the MNU Department of Alien Affairs, albeit incompetently. Near the beginning of the film, he gets sprayed in the face by a container of black liquid, infecting him and beginning his transition into one of the Prawns. After befriending one of the neglected and abused aliens, he begins to fight back agains the MNU and help his new friend escape from Earth.
Jason Cope
Christopher Johnson is a Prawn, as well the owner of the device that infects Wilkus and begins his turning into one of the aliens. He aids Wilkus in his fight against the MNU, and eventuslly is able to escape to the ship and flee from the planet of Earth.
David James
Venter is the man who is put in charge, by a private military organization, of the capture of the rogue Wilkus Van De Merwe. He is a ruthless man who is quick to strike down any and all who oppose him and he takes great pleasure in killing Prawns, despite his rarely having a reason for it.
Vanessa Haywood
Though she does not appear much in the film, Haywood was obviously the right choice of casting for this role. She is the mild-mannered wife of Walkus Van De Merwe.
Eugene Khumbanyiwa
Obesandjo is a paralyzed Nigerian gang leader. He is obviously a psycopath. He is rich, which allows him to have vast amounts of power and numerous weapons. He believes that by eating Prawn body parts, he will be able to use their weapons.
