Mark Twain’s early literary experimentation in the West gave rise to his most recognizable narrative voices, tropes, and techniques—including expressions of anger. These newspaper endeavors featured and were fundamentally shaped by invective, especially the insult, a robust and flexible form of verbal abuse. Twain used insults to establish his literary superiority, demonstrate or reinforce his various group identities, and contest his place within social and professional in-group hierarchies. This article constructs a framework for Twain’s rhetoric of insults in his western newspaper contributions prior to his 1866 trip to the Hawaiian Islands, focusing on insults in three contexts: the rivalry, the hoax, and the honor contest. It analyzes the multiple rhetorical dimensions of Twain’s varied forms of mock and malicious insults (including vehicle, intensity, and invective loci) and traces the social bonds created or affected by his insults.