on the warpath, to be/go

slang To be overtly angry and/or looking for retribution. One of many expressions often considered offensive for making reference to Native American stereotypes or tropes. I'd avoid the boss if I were you—he's on the warpath and screaming at everyone he sees.

To be infuriated enough to seek out the person or agency responsible. This Native American term was used quite literally by James Fenimore Cooper in The Deerslayer (1841) to describe a character who had never engaged in battle (“He has never been on a warpath”). By the end of the nineteenth century it was loosely used to describe anyone on an angry rampage.