Baron Krieger is a villain in the second season of DC's Legends of Tomorrow.
In 1942, the Justice Society of America is called by the President who gives them the location of Baron Krieger. The Justice Society heads there but is annihilated by Krieger's force. After learning this, the Legends head back to 1942 to save the JSA.
They arrive at a nightclub in Paris where they are allowed to enter when Martin Stein poses as a famous singer. There, Krieger turns up eventually and has a conversation with another patron. Posing as a waiter, Nate Haywood is able to listen to their conversation and finds out that Krieger plans to transport the Askaran Amulet. However, eventually chaos breaks loose when Ray Palmer refuses to do the Hitler salute. In the chaos, Krieger escapes.
Back on the Waverider, the Legends and the JSA team up and plan to take down Krieger, who is planning to exchange the Amulet in Fontainebleau Forest to someone yet unknown to the Legends. They track down Krieger's caravan and attack the Nazis, taking them down with ease. In the chaos, Krieger attempts to escape into the forest but is pursued by Vixen and Ray Palmer. Stein calls the two off Krieger's trace, allowing him to use a special serum that was given to him previously by Eobard Thawne, whom Krieger wants to bring the Amulet in exchange for more of the serum - planning to use it to create an army of super soldiers to invade the United States. After using the serum on himself, Krieger turns into a mutated beast and attacks Palmer and Vixen, knocking them out for the Nazis to capture.
Krieger then returns to the caravan, taking down one of the attackers after the other. The Legends and the JSA are forced to retreat, leaving Vixen and Palmer behind. The two are brought before Krieger, who has now returned to his normal form. He investigates Palmer's suit and, by threatening Vixen, makes Palmer reveal himself as the scientist behind the suit. Planning to make use of Palmer's knowledge to create more of the serum, Krieger leaves the two alive for the moment. When Krieger is called outside, Vixen and Palmer swiftly take down the remaining two guards. When he finds out that the Legends and the military are attacking his base, Krieger orders his men to lock down the base while he takes another dose of the serum.
He heads outside the base, attacking two of the JSA members and eventually pursuing Commander Steele. Steele is saved by his grandson Nate, a member if the Legends. The two drive off on a motorcycle, further pursued by Krieger. All three are eventually hit by the military bombers, killing Krieger and severely injuring Steel and Nate.