Arthur Putnam (September 6, 1873 to 1930) was an American sculptor. He was part of an early 20th century artistic efflorescence in California. As one resource summarized the importance of Arthur Putnam:
Arthur Putnam is known as a sculptor who became famous for his cast bronze animals. He became famous for his renditions of the animals he observed in his life including pumas, bears, coyotes and mountain lions, and he had a deep understanding of animal anatomy that started in his childhood when he had studied the skeletons of animals.
While Putnam’s oeuvre included bronzes of women, children and small animals, it was the species of big cats that seemed to fascinate him the most and their combination of menace and mystery made them his most common subject.
Though he was not a great sculptor, never having resolved the inherent issue of portraying degrees of gravity in a heavy medium, Arthur Putnam should not be forgotten.
Here is a nice biographical essay which emphasizes Putnam and Jack London's relationship.