Thesaurus Rex

One night, a young student's thesaurus disappears from her bedroom.

A trail of slimy footprints leads to the bedroom window, so she looks outside and sees the thesaurus down below in the grass.

Then, suddenly, a colossal monster unfolds itself from the pages of the thesaurus like an origami creation gone terribly wrong.

Soon, it towers above the family's house, constantly changing its form and sprouting a new weapon with each transformation!

Who could possibly defeat this shape-shifting monster made of synonyms?