take (one's) head off
1. Literally, to decapitate one; to sever one's head from one's body. The despot began taking people's heads off for so much as whispering dissent. Never, ever stand up during a rollercoaster ride, or it could end up taking your head off!
2. To criticize or respond to one in an extremely angry and aggressive manner. What's wrong with the boss today? I just tried to ask him a question, and he nearly took my head off! Look, I know you're upset, but don't go taking the kids' heads off about it.