I suspect there may be a lot of small delicate bones to remove in an Iguana. They both slither and crawl with great speed and flexibility. Such movement would require a strong ‘armature’ or bone structure, but it must also be lightweight, sort of like with large nesting birds.
Reptiles as a whole are pretty easy to clean. A lot depends on the size. The larger ones would be comparable to cleaning any small game bird, while the little ones would be more akin to sunfish, though they don’t have pinbones.
Most animals are similar in anatomy unless you’re in Australia—God seems to have populated that continent to confound our petty nomenclature system.
The tail is mostly muscle.