The Hobo Guardsman is a very unlucky individual who is harassed by Chaos champions and Arbites. He appears to be a homeless veteran with only scraps for clothes and a starving family.
Lucius the Eternal refers to him as "Hobo-chan" and harassed him with a "sandwich" made from sand and "freshly milked daemonette milk." Lucius force-fed the sandwich to him as part of his charity efforts.
Later, an Arbite claimed that the Hobo broke the law by putting rat flesh on his rations to try to give his family more nourishment. He got his legs broken, and when he told an Administratum adept that the rations tasted like shit, he had even more charges brought against him. Fed up with this abuse, the Hobo loudly declared that he was joining Chaos, which prompted Inquisitor Headsmash to Exterminatus the planet (thoug the Hobo managed to escape into the warp.