Supermegatopia

Supermegatopia is an adult comedic furry superhero setting (it's much less complex than it sounds) created by The Brothers Grinn.

Story arcs
The main storyline of Supermegatopia encompasses twenty comics, each of which has eight pages. The main storyline concerns the loose 'superteam' of Weasel Boy (and his sudden wife-to-be, Delilah), Mighty Yak, Mongoose Guy, Grease Monkey, Hyper Hippo, Elephant Girl, and Tiger Lass, as they fight such foes as Avatar, Dr. Ghoti, Skippies, and the Supermegatopia Terrorists, as well as deal with being upstaged by such more-organized (or harder-to-say-no-to) groups like the Continuity Police, the Offenders, and the Justice Legion Supermegatopia.

Side arcs
Although the main storyline has not been updated since October of 2003, there are dozens of sidestories and fanfictions on the official site, as well as a number of fan-made comics and approved crossovers. Additionally, Supermegatopia has been turned into an equally-comedic, equally-adult-themed MUCK, and a not-really-adult-but-still-furry-supers roleplaying game.

Crossovers
There are a number of crossovers with other comics, both created by the Brothers Grinn (such as Crushed: The Doomed Kitty Adventures) and by others (like Gaming Guardians). In addition, other people's characters (such as Pandora Pup, Elephant Girl, and Zig Zag) have Supermegatopia versions of themselves.