A couple of nights ago Animal Planet ran a show called "Almighty Amphibians".

It featured some large American salamanders... like the Mud Puppy and the Hellbender that grew to about 20" in length.

Then they showed a Japanese Giant Salamander that was 5 FEET long and weighed about 55 lbs. It kept trying to bite the scientists that were measuring it.

I've seen the Giant Pacific Salamander before in both Spada lake and Lake Isabel. They were about 10" long.