Appearance and PersonalityEdit
Walter is described as being tall and rangy, at least a head taller than Max, with blond hair. It's assumed that he was fit and muscular due to his strong association with fist fights.
Although little is known about him, Walter appears to be a prideful individual. When we first meet him his ego is wounded due to the fact that Max not only beat him in a fist fight, but also managed to make him cry. He "walked sullenly to Max Vandenberg" when he was supposed to raise the winning boy's arm in an act of sportsmanship and tells him "next time I kill you" after Max thanks him. He also appears to hold grudges, as he's always seeking revenge for the first fight Max beat him in. However, over the course of the years that they fought he grew to respect Max and later became his close friend. He's often described as a serious individual, but a conversation he and Max had implies that he had good sense of humor.
One can interpret Walter's anger towards Max and need to physically overpower as him having romantic feelings for Max that manifest in violence as a result of internalized misogyny and toxic masculinity. Walter is willing to die for Max (as his acts of hiding him would've resulted in his death had he been caught) so either way their relationship is intense and loving (platonically or romantically).
Walter Kugler was presumably born in Stuttgart, Germany, where he grew up with Max Vandenburg. He was involved in the street fist fights and a skilled fighter. He fought Max a total of thirteen times, having won ten. It's fight number five that Max recalls in The Book Thief, which the first of the three fights between the two that Max wins.
When he and Max turned seventeen they respect they held for one another turned into friendship and worked together until 1935, when Max was fired. Over the next three years, Walter became absorbed in his work and eventually became a member of the Nazi party, most likely to hold his job and blend in.
On Kristallnacht Walter comes in Nazi uniform and takes Max away from his family, telling him that the chaos is just what they need for Max to be able to disappear. Walter hid Max for the next two years in a place where he was formerly employed and made sure to check on Max's family as often as he could without appearing suspicious.
He went to visit Hans Hubermann in 1939 after Max's family had been taken away in hopes that he would be able to help them. He was responsible for getting Max's papers and organizing his trip to the Hubermann's.
Walter was conscripted into the German army in 1940 and sent to Poland. Nothing is said of Walter Kugler after the war in the book, though Max tells Liesel about him while hiding in the basement. Before Max left Walter gave him a razor, a spoon, shaving cream, and a pair of scissors.