My Favorite Book

When I was a child... I liked the books named Goosebumps by R.L.Stine
My favorite of these horror books was Monster Blood II.
The book is about a kid that has a green, weird and misterious liquid. When someone or something drinks this liquid it trasforms in a monster by becoming aggresive and giant.
This kid brought the green liquid to school and left it in the classroom near the hamster´s cage .
So the hamster drank the liquid and became a terrifying monster! A huge, dangerous and lovely hamster! How can this kid solve this problem? Well... maybe if you´re interested in the ending of this awesome story, you should buy the book or just ask me for it.
I´ll be pleased to lend it to you ;D.