Does Hoppers have a post-credit scene?

Yes, Hoppers has a post-credits scene, and it pays off a small joke from the first act.

Earlier in the film, Mabel goes door to door with a petition, and one man — rather than signing it — uses the page to write out his shopping list. It is a throwaway gag about a person too self-absorbed to notice what is being asked of him, and the film moves on without comment.

After the credits, there is a knock at his door. He opens it, and finds his petition page handed back to him: every item on his shopping list is ticked off, and Mabel's name has been written in as a signature, with a smiley face. Then he looks down, and a column of ants is filing into his home carrying the groceries.

What makes it land is that it settles the film's actual argument. Hoppers is about whether the animal world and the human one can be made to negotiate with each other, and the man in the doorway is the film's small portrait of human indifference — not cruel, just uninterested. The stinger has the animals answer him on his own terms: he wanted his shopping done, so they did his shopping, and then they took his signature. It is both a favour and a transaction, which is exactly the relationship the movie has spent ninety minutes arguing for.

There is nothing else after it, and it does not tease another film. It is a punchline, and it is worth the wait.