Does this sound fishy or a scam?

This is a common scam. You see it for anything a person is trying to sell. They want the item held, it's just what they wanted, it's perfect and just what they had in mind. Anybody who has a "shipping agent" is just trying to put distance between himself and the scam he's trying to pull. The "extra money" is just his attempt to 1) get you interested in his scam, 2) get more money out of you. The check or money order he sends you will be a forgery or a counterfeit. You give the extra money from being overpaid to his "shipping agent". When the bank gets word that about the counterfeit or forgery they take all the money back out of your account. You, of course, have no way to find or contact this buyer that actually leads to him. Do not try to cash the money order or check. Ignore any further communications from this person. Certainly don't give anybody your puppy. Who knows what they may do with it. They don't want the puppy, they just want to scam money from you.