I can't identify this fish!! Help!!

[peteseibold]

I caught this "thing" in a freshwater pond with lots of lilies and wood. No one has been able to tell me what it is.
Please help me identify it. I never officially weighed it, but it was 20.7 pounds.

I hope it's not the world record, because I don't think the pictures are proof enough. I just want to know for myself.
[signature]