The desire to cause someone extreme pain and/or suffering. The frying pan reference comes from the Disney movie "Tangled."
Person 1: Man, I just ate that entire dish of brownies on the counter!
Person 2: Dude, I made those for my friend!
Person 1: Sorry, dude.
Person 2: You frustrate me so much, sometimes I just wanna hit you with my coal-hot frying pan!