It's not a hump as such ,rather than his spine sloping down into his tail , his spine seems to stop in front of his legs then suddenly slope down into his tail.I ve looked at old pics and it's always been a bit like it.Ok so that is good- is the hump/ bump getting bigger? You may need to get him into a reptile vet---- heres a website to find one -- if your in a small area / town type in a bigger cities website closest to you
www.arav.org
in the meantime I want Tracie to take a look to see what she thinks
His tail looks good - its thick / fat
@Drache613