I've had quite a few 'eggs gone wrong'....softies and thin shelled, slab sided and corrugated, spray booth and bloom glitches, dime sized fart eggs and 3.5" double yolkers, blood/poop/coating/bloom smeared. They can be alarming and then fascinating.
Here's hundreds of them:
https://www.backyardchickens.com/threads/weird-or-odd-eggs-pics.697007/
Here's hundreds of them:
https://www.backyardchickens.com/threads/weird-or-odd-eggs-pics.697007/