Talk:Adventures in Ponyville/@comment-4148106-20110721212229/@comment-66.185.12.106-20110820123838

I think it's more of a play on the phrase "mount up", actually, which is a term that means it's time to go or move out--particularly in battle or other tense situations. It dates back to the cavalry days. It also may be an intentional pun on the slang phrase (at least in the U.S.) "pony up", which refers to paying money for something. As in, for example, "pony up the dough", which means coming up with the money to pay for something.