Got this penny in change today and at first glance I had a "Did I just find a 1943 Steel Penny?" moment but turns out it's just a penny missing the clad layer.. not sure if this is something that happened at the mint or was done artificially... Pretty beat up but kinda cool
1988 Cents are Copper Plated Zinc planchets. They are plated and not Clad. Quarters, Dimes and Kennedy Halves are Clad with a copper center core. I think you just have Environmental Damage.
This brings up an interesting point. What would the modern cent look like if it really got a lot of circulation? Wouldn't the thin copper coating wear off fairly quickly? When it did the zinc under it would start to corrode. Zinc is not a good coinage metal for that reason.