I've got a couple,

One time when feeding this Hognose I used to have he made the pinky burst its guts out, which was a tad nasty, although I don't get grossed out by that stuff.

Another time I was trying to feed my male normal Ball python a jumbo mouse (F/T) but he wouldn't take it, but something sort of odd happened.. I guess you can say the mouse had her menstration cycle