Penny (Dr. Horrible's Sing-Along Blog)

Penny is the leading lady of the internet mini-series "Dr. Horrible's Sing-Along Blog". She is the only genuinely good character in the film, as one of her lovers, the main character, Dr. Horrible (also known in "normal life" as Billy) is technically a supervillain (though he has positive aspects), while his archnemesis, Captain Hammer, though technically a superhero, is ironically more villainous than Horrible. She is an idealistic and generous woman who volunteers at a homeless shelter.

Penny is first met by Dr. Horrible (posing as Billy) in a laundromat. She asks Dr. Horrible to sign a petition to turn a condemned city building into a homeless shelter, but because the remote he's using requires his attention, he doesn't seem interested in her and her cause. Penny leaves, but because of the evil superhero Captain Hammer, who takes over Horrible's song and smashes the remote control, he inadvertently makes the van veer over Penny, but he pushes her out of the way and makes it appear like he stopped the van with his bare hands. Before Hammer can beat up Horrible, Penny thanks the former for saving him, and they go on a date.

One day, Penny waits for Billy to share frozen yogurt with him. The opening day of the homeless shelter, where a statue of Captain Hammer will be uncovered, she eventually begins to realize Hammer is a narcisstic jerk when he speaks of having sex with her in his speech. She quietly attempts to leave as the crowd joins in Hammer's song, but Dr. Horrible interrupts and freezes him with his freeze ray. Later, after Captain Hammer is revived, the two fight, only for the death ray's blast to hurt Captain Hammer for the first time in his life (because Hammer denied Horrible's warnings about the death ray). It is later shown that accidentally, Horrible had killed Penny, whose last words are that "Captain Hammer will save us." She then dies, much to Horrible's sorrow, causing Dr. Horrible to declare Pyrric victory, and thus, he is granted entry into the Evil League of Evil, which gives him all he ever wanted but the one thing he wanted most.

Penny is played by Felicia Day.