Boris is one of the bounty hunters along with Jujunga, The Gentleman, and I and Am who team with Princess Mira to take done Jack and serves as one of the main antagonists in the season 4 episode of Samurai Jack titled "The Princess and the Bounty Hunters". He is a bounty hunter sent out to destroy the titular protagonist, like many other villains in the series.
Boris is the strongest on the team, but is not as good as the other bounty hunters at evil plans, but think of his plan as superior to others. He expects Jack's sword break on Boris chest armor and Boris "Breaks him, Breaks him, Breaks him!", which would end up failing. He and Princess Mira do not get along very well, and dislike working toghetter. They constantly argue over which plan is better, and end up staring each other down. However, Everyone agreed to go with Mira's plan.