My first thought was Verdigris but now I'm not so sure. It almost looks like green chewing gum. Try some acetone first. https://www.cointalk.com/threads/green-verdigris-on-coins.211198/
LOL, @TIF has the perfect vid on one of her coins. This would be AFTER hitting the bong on her coin...
I have not received the coin yet but it does not look like verdigris to me. Just seems kind of weird looking.