Penny 1982 Post Mint Damage. How?

maybe hit with a hammer

what ever caused this, it is PMD.

As to how,we can guess all day and not guess right. Congrats on 50 post Mike
John1

A coin that's all bent and twisted, with pieces partially torn away from it, I would usually classify as "caught in high-speed machinery". Outdoor gardening equipment like a lawnmower, wood-chipper, or weed-whacker, are probably the most common origins of machine-vs-coin damage, since such devices are likely to hit a coin dropped in the foliage and then the coin is found on the ground some time later, by a metal detectorist or casual passer-by. The environmental damage (staining) seen on this particular coin also leans me towards that hypothesis - it was lost for some time after being damaged. A coin could fall into some other kind of large piece of industrial machinery and achieve much the same effect. Or, you could fire the coin out of a rail gun or maybe even a slingshot, and you might get the same effect if it hit the target edge-on - in which case, it would be high-speed coin hitting stationary object, rather than high-speed machinery hitting stationary coin.

Ultimately, speculating about causes of PMD is just that - speculation. Unless you or a reliable witness actually saw the damage take place, there's no way to know for sure.