If I'm really good, I'll come back as an otter.

Otter.com is a very cool site.  You want to know something about the 13 species of otters?  This is a prime place to start.  And don't overlook the links page -- it's as long as your arm.

North American River Otter page, from the Lioncrusher site. 

Jimmy's Sea Otter Page

"I've Got This Thing About Otters"