I was going to suggest an african clawed frog. They really are beautiful creatures and swim very majestically. They are also fully aquatic.
However they like their temperatures much cooler than that. I've been told between 68-72-ish range. Right now I'm keeping mine in the mid-high 70's, but doing things like having a fan on can help some heat problems (along with a well ventilated lid).
Also african clawed frogs are hardy, good for beginners, and relatively cheap! Just don't get any tutti fruitti or jellybean colored ones. They have been cruely dyed and purchasing just adds to the business. Look for maybe an albino or "wild type".
Check out more info on the google about these fascinating animals.
