A monster hit at the box office; ate a monster steak.
A monster of selfishness.
An example of a monster is a person who orders others killed just for his own amusement.
An example of a monster is a child who cannot behave in public and who throws temper tantrums all the time.
An example of a monster is a huge book that is 5000 pages long; a monster of a book.
An example of a monster is a an imaginary frightening creature that your child fears is hiding under his bed at night.
That dude playing guitar is a monster.
Have you seen those powerlifters on TV? They're monsters.