There's an alien empire that claims to rule the sector of space that Earth is in. First contact was in the '60s, and everything was tense, nervous – fingers on every metaphorical trigger.
And then they walked out, and they looked like puppies.
Specifically, cocker spaniel puppies with mottled green and blue coats. As you can imagine, things didn't go badly after that; though Earth didn't acknowledge their supremacy, and they didn't acknowledge our sovereignity, in big-picture terms, everyone had other things to think about – Earth with all its net.humans would be too difficult to conquer, let alone the headache of keeping it that way, and there was really no reason; it wasn't in a strategically useful place, nor did it have any especially unique resources. Relationships have been cordial except for one stunningly ill-advised and thankfully short-lived attempt at a war in the '80s.
Doctor Puppy is a member of this species.