Undecided Question

I want a Iguana For Christmas And i have a Few Questions.
How long does it take for them to get fully grown and how big, i heard 5-6 feet im pretty sure that's True,Just Making sure.

When They Are Fully Grown Can i just let it Roam Around in my Room or do i need a cage?

What do they eat

Is it a good pet

If i let it roam around in my room will it eat my Gerbils or rip up my mattress

u needa cage they do grow big but i dont think that big umm lizards will bite and they do hide and they neeed warm air if ur more curios go to pet store ask about them

bridges pets (pet store)