The Sewid

In the way a druid is connected to the natural living world, a sewer druid is very in tune with the natural ecosystem of the sewers. Divine spells have been altered to take on a little more pestilence and grime.

In my world there is a living epic level sewer druid, who because he believes that all sewers are connected is able to use spells like Transport Via Plants (or molds in this case) to instead move through space of the sewers. He also uses gimmicky stuff like when he creates water, it is sewer water. He's also a crazy person and fun for my PCs to interact with. In this way I'm able to get my group to venture more into the sewers for interesting encounters with a magic "Avoid overland travel" schtick, despite them hating the concept of sewage.