Vaughn Armstrong is one of the longest-serving actors in the Star Trek franchise, having appeared in every Trek series but the original. He has played twelve different characters over the years - a record unmatched by any other actor in Trek.
Armstrong's first appearance in Trek was in the The Next Generation episode "Heart of Glory" in which he played Commander Korris, a renegade Klingon who stole a cargo ship and tried to use it to attack his fellow Klingons (whom he believed had gone "soft"). His other characters are: