Captain Hammer is a fictional superhero character from the web series Dr. Horrible's Sing-Along Blog, created by Joss Whedon. He is portrayed by actor Nathan Fillion and is known for his charming personality and over-the-top heroics. Captain Hammer often battles the villain Dr. Horrible, played by Neil Patrick Harris, and is characterized by his self-importance and desire for fame. In the series, Captain Hammer is depicted as a classic superhero archetype, embodying traits such as bravery and strength. However, his character also serves as a satirical take on the superhero genre, highlighting themes of ego and superficiality in heroism.