: A massive mutated larva. The character's vocal effects were provided by the film's co-director, Conrad Vernon [10, 20]. Human and Alien Characters
: Voiced by Renée Zellweger and John Krasinski , respectively. They play a couple whose date is interrupted by an alien landing [10, 37]. Monsters V Aliens Cast
: Voiced by Stephen Colbert . The impulsive and dimwitted President of the United States [10, 25]. : A massive mutated larva