That is a sizable interior die break,it kinda looks like squidward,. Very heavy polish marks and roller dmg.
I hope people learn from @juslystn that even miinor errors can be super fun to find, especially when you are the one finding them. Nice stuff there!
Three thing... 1. Cool find... 2. Suck about the coin rolling machine marks 3. You have some corrosion happening that you may need to take care of...