 The Alphas were given a definable head area to show their status as more sentient, while receiving a different color and a bigger size compared to the Mimic grunts.Cinesite created the mechanical Mimics used in the training areas, while MPC created the Omega in a digital environment into which the effects artists composited underwater footage filmed at Leavesden's water tank.Animators created digital versions of the battle suits, at times with the soldiers inside them.