This coin was advertised as 'Greek', but I am more inclined towards 'Celtic'. (Perhaps Durotriges.) I have found that some coins are even described as 'Greek Celtic'. I am afraid that my knowledge in this area is lacking and I am hopeful to get ideas from some others who are more knowledgeable than I, when it comes to these types of coins. I can tell you that the coin is AE10mm., and 1.10 gm. It appears to have a galloping riderless horse on one side, and four pellets in a square with four more pellets outside the square, on the other.
I think your coin imitates Maroneia in Thrace. On the originals, the reverse depicts four bunches of grapes within a square. https://cngcoins.com/Coin.aspx?CoinID=158424 In my opinion, the label "Celtic" is sometimes applied too easily. I'm not saying it isn't Celtic but attributing it as such requires more evidence than recognizing it more generically as an imitation.
Nice coin. I don't recognise it as a known Celtic one, and it's definitely not Durotrigan. I'm not sure what it is, but hopefully someone will be along soon with the answer.
Be careful if this is from a certain UK EBay seller. He specializes in crude designs and has now switched to bronze/copper from a silver-type metal. "Celtics" are a prime target because of their often crude designs, but this is cruder than most. I recently also came across another seller attempting to pass limes denarii off which were obviously cast in dark metal. A look at the seller's other coins convinced me that their entire lineup was fake. I signed them up for Forum's Notorious Fake Seller's List. Lots of fakes out there. Caveat emptor.
Maroneia imitations such as yours are relatively common. Style varies but the prototype is always recognizable. Yours is more appealing than many, I think. Only on eBay do they seem to be called "Celtic". Here are several that popped up on acsearch:
