Yes, a 20 gallon should be good. About 3 to 4 inches of coconut substrate and a water dish that is big enough and easily enough for him to get in. I use a plexi glass cover with about 25-1/4 inch holes drilled in it. This is to help hold the moisture in.

TJ, I agree on the head to body, but the overall size may puch it more toward male. A front pic would help to see the throat. Any orange around the shoulders?