Mine doesn't do anything too nuts anymore. It'll usually go flat and lose some curl wherever I've slept on it, and it also gets frizzy at the ends and a little oily at the roots. Annoyyyying. When I dyed my hair a lot more and it was more dry and damaged, I would wake up with the coolest bedhead. It would be huge and all over the place, cut in a way that it was choppy and would form into individual locks. Flat parts would spring back up with a good tousle and shake of the head, and oil wasn't such an issue cause my hair needed the moisture, haha.
Usually I wash my hair before bed but If I don't put it in a french braid I wake up with perfectly straight shinny hair I know I should love it but it's so boring so I usually put it in a french brain when it's wet so I wake up with wavy hair.