I've been in many many mosh pits and have had several semi serious injuries from them heres a short list of the worst or best:

1) two fractured ribs
2) broken nose
3) broken bones in the right elbow including my funny bone
4) dropped on a dividing rail at brixton academy whilst crowd surfing (back down)

concussion has been inflicted on me many times more than I can count. As for funny things:

Picked up and thrown towards the back of the brixton academy

crushed by 70,000 people and have the girl behind me apologise for doing it

loads of things have happened in mosh pits but some are funny others are just painful