This is Hans Baluschek

Hans Baluschek (9 May 1870 – 28 September 1935) was a German painter, graphic performer and writer.

Baluschek was a prominent representative of German Critical Realism, and as such he sought to portray the vivaciousness of the common people with luminous frankness. His paintings centered on the lively class of Berlin. He belonged to the Berlin Secession movement, a group of artists eager in avant-garde developments in art. Yet during his lifetime he was most widely known for his fanciful illustrations of the popular children’s book Little Peter’s Journey to the Moon (German title: Peterchens Mondfahrt).

Hans Baluschek, after 1920, was an active fanatic of the Social Democratic Party of Germany, which at the time nevertheless professed a Marxist view of history.