Curious as to why you went ahead and did all the banners and the other things if you hadn't heard from him or received funds.
Your emails show you constantly trying to get money from him and getting no response which should've told you to slow down and don't do anything until you heard from him. A email saying check is in the mail is not something to hang your hat on.
You were on notice yet continued to ignore all the signs.
He finally said I'll send a check. Maybe you should've stop all advertising until you received funds.
I haven't seen any contract. It's just emails and nothing legally binding. I'm sure you know the reptile business is as cut throat as any business so signature on the dotted line should be required.
My opinion and my opinion only is there is no contract, which requires a meeting of the minds and I don't see it in this case therefore I don't know why he would come here to respond.
( i just like this smiley)