What do copper pennies look like?

It depends on which country issued them, and when. Please post a new, separate, and more-specific question.

The reason a single answer is difficult to provide is that there are hundreds of possible choices. Pennies have been minted for over a millennium in the UK / England. At one time countries that were part of the British Empire like Australia and New Zealand also used pennies. Finally, the US and Canada have minted 1-cent coins for at least 150 years and these are commonly called pennies in both of those countries.