When a meteorite from outer space hits a
young girl and turns her into a giant monster,
she is taken to a secret government compound
where she meets a ragtag group of monsters
also rounded up over the years.
On her wedding day, Susan Murphy (Reese
Witherspoon) is hit by a meteorite infused
with Quantonium, a rare and powerful element
that causes her to grow to an enormous size.
Targeted by the government as a monster,
Susan is captured and imprisoned at a secret
facility where other such oddities are being
held, including Dr. Cockroach (Hugh Laurie),
a mad scientist who accidentally transformed
himself into a roach-human hybrid, B.O.B.
(Seth Rogen), a gelatinous, brainless mass
brought to life in an experiment gone wrong,
The Missing Link (Will Arnett), a Creature-
from-the-Black-Lagoon-like lizard man, and
the skyscraper-sized mutant larvae Insect-
osaurus. When deranged alien overlord
Gallaxhar (Rainn Wilson) arrives on Earth to
obtain the precious Quantonium and conquer
the world, President Hathaway (Stephen Colber
t) offers the monsters their freedom in
exchange for defeating the evil mastermind
and his legion of robots and clones.