Cock-teasing us with that greatest joke ever written, eh?
Neato 500th edition filled with references and throwbacks to past strips you've made, it's the little things like the lighting emanating from something that's obviously supposed to be glowing, the smudges in the ye ol scrolls, the blur of things in the distance and the textures in backgrounds/characters are always nice to see, a display of how much detail you like putting into all your works. Plus a cool continuation from the 200th and 250th specials.
There are a few slightly useless panels like when the King's telling the story and he just suddenly stops, looked a bit like you were just trying to give another row of panels but who knows, it might've been some joke I totally missed. Also the text used in those scrolls could be a tad hard to read sometimes, had to click the comic and zoom in sometimes just to read it.
Really liked it, both looking forward to whatever next special you make and to see both Dave and Carl in their day to day life. Here's hoping you get to the 1000th eventually!