What is the fine-grained topic of the following text: I plan to lurk like the phantom of the opera just to get a feel for how this works, but my background is as an illustrator with a particular interest in marine reptiles and sharks (if any one has any ideas on the physical appearance of Squalicorax, I'd be grateful...). Only return the topic.
Interest and inquiries about marine reptiles and sharks illustration, specifically Squalicorax.