They got horses to trade.
4 seconds sound clip from the The Outlaw Josey Wales movie soundboard.
You can hear this line at 00:51:08 in the Blu-ray version of the movie.
Quote context
[...]
- They're going down to Mexico. I think I'll join them.
- I didn't know others hadn't surrendered.
- You haven't got a horse. What do you plan on doing, walking to Mexico?
- No, there's a trading post right near the Creek Nation.
- All I have is a piece of hard rock candy. But it's not for eating. It's just for looking through.
- Alrighty. I'll get you a horse.
- Muskrat.
- Muskrat? What the hell's that?
- Muskrat.
[...]