The Underdog is a 1943 American drama film directed by William Nigh and starring Barton MacLane, Jan Wiley and Charlotte Wynters.
It is a story of how a dog overcomes his fear of fire when his young master is endangered by saboteurs.
After losing his farm, a man moves to a small town in World War II. His elder son is away serving in the army, while his younger boy struggles to fit in and clashes with a neighbourhood gang.
Production started in late July 1943. The film was released on October 10, 1943.
Because of the presence of scenes showing sabotage, the War Department rejected this film from export.