Check out this conversation if you haven’t heard of this AU yet, it’s what I’m basing most of my thoughts here on.

1. Though I’ll be referring to him as “Courage” in all these headcanons, that isn’t Courage’s name in this AU. In canon Muriel gave Courage his name when she found him because she thought he was brave. Stan named him “Max,” after the Jewish champion boxer Max Baer, because he knew this little dog had to be tough to survive on his own.

2. The “tone” of this AU is a little closer to Courage the Cowardly Dog’s “dark but wacky” feel than standard Gravity Falls. As in CtCD, no one notices or comments on the fact that Courage walks on his hind legs, or understands him when he talks. Also as in CtCD, no one seems to think it’s too weird when Courage’s “pantomiming” turns into full-blown shapeshifting. Ford is the only one who’s really suspicious of him and convinced he’s supernatural, but it’s more “there’s something weird about that dog” than “am I the only one who just saw him transform into a chicken for a minute?”

Ford is always trying to get a closer look at Courage or do some tests on him, hence why Courage is afraid of Ford.

3. Stan hurt his leg when the apocalypse was averted, and while he’s healing Courage helps him out with the chores and gets things for him a lot. In keeping with headcanon #2, Stan doesn’t see this as a sign of anything other than “my dog is really smart!”

4. This:

“What? It’s not illegal if he’s a dog. There’s no such thing as dog jail, Ford.” (Courage is extra smol because he’s still a puppy.)

5. One day Stan has to leave town for a few days to get some supplies for the Shack (think a Keystone Motel situation.) He makes Ford promise to take care of Courage and “not do any weird science stuff to him.” Ford promises, but Courage is still scared as heck and doesn’t want Stan to go.

All weekend, Courage is waiting for the other shoe to drop. Courage sees him hiding something behind his back, but turns out it’s just a ball–he just wants to play with Courage. Ford talks about making a special dinner and Courage worries it’ll be drugged or something, but it’s just a nice, homemade meal that’s nutritionally balanced to be good for doggies. He takes Courage in the car and Courage freaks, wondering where they’re going, turns out he’s just taking him to the park. He acts like a perfect, gentle, loving pet owner the whole time, and by the end Courage is even comfortable enough with Ford to sit on the couch and let Ford pet him.

The night before Stan gets back, Ford comes up to Courage and bends down, saying “I think we might have gotten off on the wrong foot. …I don’t want to hurt you. Really. I just want to learn more about you.” He tells Courage that he’s been good for Stan, and that he seems like a good dog. Then he suddenly grabs Courage by his scruff and gets all in his face, and says “but if you turn out to be some kind of soul-eating, planet destroying monster hiding under a cute furry facade, just know that nothing, not even my brother, will be able to stop me from chopping you into tiny bits and keeping you in individually labelled jars. Understand!!?”

Then he drops the traumatized little dog, cheerfully wishes him goodnight, and leaves.