The still unknown man was told by a ticket controller in Magdeburg to show his ticket, but instead beat the 55-year-old transport worker “to a pulp”, police said on Sunday.
The man repeatedly punched the controller in the face, police report, and then kicked him in the head after he had fallen to the ground.
Other passengers on the regional train tried to intervene, but were unable to prevent the perpetrator from fleeing.
The train attendant was taken to hospital due to his serious injuries.
Federal police - who oversee Germany’s transit hubs - are investigating the attack as grievous bodily harm as well as fare dodging and are currently reviewing surveillance footage to identify the suspect. They did not provide a description of his appearance.
On Saturday in Stendal - also in Saxony-Anhalt - two visibly drunk fare-dodgers also caused trouble for federal police when officers tried to get them off a train. The older of the two men, 44, pushed one of the officers against a wall and tried to flee, but police were able to overpower him. The 22-year-old tried to escape as well, but was also caught by police.