The Webcomic Roommates has Loads and Loads of Characters and cameos (more than 100)... this list is far from complete, and still had to be split to multiple pages. Also these pages can be quite spoilerific.
- The Building #42
- Townsfolk of the unnamed university town
- Visitors or people not living in the town
- The magical community
- The Many Faces of... various characters (As thanks to the ensuing shenanigans there are several versions of some.)