Rats and Iguanas

Ok, so my birthday is in december and I asked my mom if I could have a pet rat. She said no, so my aunt Julie is trying to get me to ask for an iguana. My mom now says I can have a rat if I pay for bedding and food. So now Im not sure if I want a rat or iguana. lol, both are kinda weird pets, but thats what makes them so cool! Aunt Julie says she has either a little mouse or rat living in her house that she cant catch. She doesnt want to set a trap and kill it, because its a baby. If I could catch it, I might be able to keep it. But then again, it is wild and iguanas are still kinda cool. I guess either way I get a pet that sits on my shoulder lol!
What do yall think would be better?