Dudley's dungeon is the webcomic once hosted at http://dudley.nicolaas.net. It was finished on the last day of 2008. However two new versions appeared soon. One is at http://sadowl.com/dudley/index.php and uses the same code as the original version; unfortunately, it has (as of 2017) no new comics since 2013. The other is at https://alt.org/nethack/dudley/ created by paxed and has several differences, most notably colors and graphical editor. The source code for this comic is available at https://github.com/paxed/dudleysdungeon and it is (as of 2017) still active.
This webcomic is set in NetHack. Our hero, Dudley, wants to obtain the Amulet of Yendor. The webcomic is in ASCII, like NetHack in tty mode, so you can read it even if your web browser does not load graphics. However, do not forget to set proper options when reading it from a text browser (such as w3m or lynx), since otherwise popup explanations will interfere with the text of the comic.
Anyone may design and submit, to either of the two new sites, their own version of a Dudley comic for it to be commented and voted upon when published.
There was a Comixpedia page about the webcomic; here is an archive: