This isn't an April Fool's Day post - it seems I ought to get that out of the way.
Having begun in 2008, Rick Griffin's Housepets! is a mostly-comedic webcomic about the various pets (primarily cats & dogs) who populate the town of Babylon Gardens. Like many series born from comic strip ideas about pets, the animals in this comic speak English, stand on two feet, manipulate objects as though they possessed fingers & thumbs and are generally treated as members of their owners' families, rather than mere possessions.
Unlike most strips, Housepets! attempts to follow through on some of the implications behind a world where pets possess all the intelligence of humans, but enjoy few of their privileges. Er, that is, the series explores these ideas when there's a joke to be mined - it's really not a dramatic saga. Usually.
If Housepets! were only a gag-a-day strip, I wouldn't be posting about it now (or any other time). Heck, I didn't get very far into the series run on my first attempt - but eventually I reached the introduction of King. First introduced as a human named Joel who works with PETA (albeit under some misgivings), Joel is punished by a cosmic being by taking on the form of King; the next few years of the comic essentially revolve around King's arc. While the animals of Housepets! enjoy liberties we in the real world would never permit our own pets to enjoy (I doubt many dogs could manage an allowance), it's still horribly demeaning for a human to live as an animal in this world.
And yet, King has evolved over time, gradually developing friendships with his fellow pets. Although he remains a pessimist at heart (a difficult habit to break, considering the cosmic embodiments of the universe have basically affirmed that yes, he's a pawn), his humility and overall vulnerability render him an easy character to relate to. At the point I'm writing this, King has reached a point where he's probably much happier as a dog - so naturally there's a looming threat on the horizon that he'll become human again, which should make for good drama (also, comedy).
Of course, there are dozens of characters beyond King (King receives a major focus about once a year) and I've come to enjoy their tales as well - but starting with King's introduction as Joel (found here), I've been truly enamored with the series. Three times a week I have Housepets! to soothe my nerves; good deal.