Horse & Rider - 1 Monster?

Hey guys. I'm working on an Eberron campaign setting for DW, and I was wondering how to handle making the Valenar cavalry or the halfling dinosaur-riders. Should I make the rider and mount as 1 monster, and if so, how would it work when the mount or rider dies?

uh, I think you can go both ways. I prefer to have them as separate stat blocks. If you go with just one stat block for both, I think that when the mount or the rider dies, you should just switch to appropriate stats for what it's left. But if they are totally bound together (like, both of them have no meaning as a single monster if separated from each other), then killing them all is clearly an option.