It is the memoir of a blue-furred dog named Raine. In the present, she's an anthropomorphic dog who can mingle with humans as well as other animals. But it wasn't always that way, and it is suggested that she helped make it that way.
She started out an almost ordinary puppy. But she loved her first owner so much that she learned to speak and read English (among other things) to be like him. He could forget she was a dog — which proved to be their undoing.
She was spayed because she "molested" her family's son, and sent to the suburbs. The new owners kept her tied to a tree without human attention. This drove her crazy (explaining a lot about the "present day" strips), so one day, she took off her collar...
A first attempt at starting the comic began in 2009. Reactions varied from complete apathy to utter condemnation. The first bubbles of discontent toward the comic occured when Simpson published a non-story comic where Raine Broke The Fourth Wall to talk about "red dogs" and "blue dogs", not so subtly taking aim at Red State/Blue State politics, specifically at the Republicans.
Fans and non-fans alike were not pleased with Simpson's allegory, and even if you didn't find the idea of doing a comic where a major plot point involves a dog making out with a young boy to be weird, some people couldn't get past Simpson's left-wing politics, which had already started to grate on some fans due to I Drew This, although Ozy and Millie tended to avoid this because it wasn't really a politically-themed comic.
In 2011, she decided to restart the comic, with the few pages she happened to post went past Darker and Edgier by having Raine Dog apparently being assassinated (akthough it's an Ambiguous Situation), leaving the rest of the story to be told in flashback. Putting aside that she opened on a dark note, the new opening looks very much like Raine was being set up as a Martin Luther King of her universe. However, after posting only one new page, Simpson abandoned Raine Dog altogether to concentrate on the project that became Phoebe and Her Unicorn. In 2016, Simpson wrote a blog post in which she frankly discusses Raine Dog and why she gave it up.
- Accessory-Wearing Cartoon Animal/Barefoot Cartoon Animal/Fully Dressed Cartoon Animal/Half-Dressed Cartoon Animal: Rainedog has been all of these in the comic and its associated artwork.
- Amazing Technicolor Wildlife: As noted, Raine has blue fur. Of course, this is actually a political commentary associating Raine with liberal, "blue state" Democrats.
- Author Avatar: Raine
- Bestiality Is Depraved: Among the more shocking elements of this series is the suggestion of bestiality. Though the protagonist's action never equate the concept, it is alluded to and contrasted. The fact that this was supposed to be a comic deconstructing the relationship of cartoon humans and animals in contrast to real-life humans and animals doesn't make this any better.
- Carnivore Confusion: Raine's refusal to hunt means she has to scavenge from garbage bins. By the present, she's become a vegetarian.
- Continuity Reboot: In April 2011, Simpson restarted the comic from the beginning and took down all the old pages... only to abandon it after posting only one page of the new version.
- Darker and Edgier: Than most of Simpson's past (and future) work.
- Dog Stereotype: Mostly averted.
- Earn Your Happy Ending: Implied by the contrast between Raine's Dark and Troubled Past and her present day contentment.
- Glasses Girl: Rainedog, in the present day.
- Go Mad from the Isolation: Raine suffers a mild case of this when tied to the tree.
- Humans Are Bastards: Not all of them, but enough.
- Interspecies Romance: Raine and Boy sharing a kiss leads to her getting spayed.
- I Was Named "My Name": Inverted. Raine's old name, Princess, was abandoned when she joined the pack of wild dogs. "Names are how humans know us. We have no need for them."
- Lions and Tigers and Humans... Oh, My!: The entire comic is a Deconstruction of how this trope would work if animals could talk—but were treated no differently than animals in Real Life.
- Orphaned Series
- Sliding Scale of Animal Communication: A bit ambiguous. At the start of the story, it could either be Level 0 or Level 4 (for Raine herself), but it seems to reach Level 5 or Level 6 by the present day.
- Talking Animal: All animals, apparently.
- Walking the Earth: Raine does this for a while after escaping from her neglectful owners.
- What Measure Is a Non-Human?: Not much, even though they can communicate with humans.