He's...his natural form is one of the big glowy tentacled mantis-like...things. The all powerful ones.

Hmm...odd that they'd try to get past Carter/O'Neill...they never really seemd to emphasize or directly address it a lot, anyway...

I'm not sure Teal'c actually understood WHY jello wrestling was popular,,,he may have just thought it was a sport. "Call Daniel." Should have been all the info he needed, though...