1. I decided to get out of the house until my father calms down. He was really on the warpath when he saw that I had damaged his new car.
2. The manager is on a rampage because he found out that the company management doesn’t plan on keeping him when they close his department. He’s really angry.

The expression originally referred to American Indians, who were described as on the warpath (literally on the way to war) when they were preparing for a fight.