I'd say he's the runt of the litter.
2 seconds sound clip from the Back to the Future Part III movie soundboard.
You can hear this line at 00:30:38.804 in the DVD version of the movie.
Quote context
[...]
- You ain't Seamus McFly. You look like him, though, especially with that dog-ugly hat.
- Marty... Eastwood. Clint Eastwood.
- What kind of stupid name is that?
- I'd say he's the runt of the litter.
- Take a gander at them moccasins. What kind of skins is them?
- What's that writing mean? Nike? What is that? Some sort of Injun talk or something?
- Bartender, I'm looking for that no-good, cheating blacksmith. You seen him?
- No, sir, Mr. Tannen. I have not.
[...]