Any ideas on a good pet for a college student?

I really want to get a pet this year, but I am limited on what I am able to have.
I’ll be living in campus apartments so I’m only allowed to have a pet that can be kept in a 10 gallon tank. I really don’t want a fish, but I don’t know what other animals I could have in an area that small. I know I’ll have to invest time and money into any pet I get, and I am willing and able to do that.
Any ideas or suggestions will be greatly appreciated!
Thanks in advance.