A person who gets really mad when they are sleepy. They also generally look disheveled. They might bite or otherwise harm you if you approach them while sleeping.
Grumplestiltskin over here bit me because I sat next to her on the couch while she was asleep
A person who is a real pain in the ass, and finds ways to turn ordinary tasks into prolonged experiences by being a grump. Mainly occurs when the female species is bleeding out for 7 days without dying.
Person A: Wow Christine was such a grumplestitskin last night.
Person B: Yea, she must've had sand in her vagina.