Interesting, but monolithic

[codeGlaze]

Having everything rolled into a giant HTML file is... Less than ideal.

Breaking it up so things can load as needed would likely be better.

[Ozzard]

I reckon this ends up as four pieces:

• "a" JSON file with all the stats per creature in (might be one per creature, but I'm not convinced it helps as it's just more roundtrips to serve this to a browser);
• A lump of script to do the display and selection of creatures;
• A lump of script to do the rolls and output display;
• A page as a holder for that lot.

Do everything in JS and throw away the PHP completely, moving the present server-side stats into the first of the files above. As a useful side-effect, no server-side processing is then required.