What college are you going to?
I went to an Environmental school for undergrad. At the time my only pet was a blue land crab Cardisoma guanhumi named Mr. Bubbles.
He was gigantic and semiaquatic and there was no possible way to conceal a large, elaborate enclosure like that in a dorm room. What I DID do, though, was make a deal with one of the biology professors to house the animal in one of the lab rooms.
See if you can make a deal like that with one of your professors.