Why does this CPU look like it got run over?

[watdahel]

http://cgi.ebay.com/AMD-Athlon...VWQQrdZ1QQcmdZViewItem

 

[Noubourne]

Oxidation. Being clamped down under a heatsink with little O2, it takes time, but it will still happen. The nickel plating does a great job of protecting the copper, which would corrode much faster, but even the Ni won't last forever.