He got a Ph.D in Horribleness and Billy is his name.
Dr. Horrible's Sing-Along Blog was posted online in 2008. It is the brainchild of Joss Whedon and stars Neil Patrick Harris, Nathan Fillion and Felicia Day. There's also a crime boss named Bad Horse. He's the thoroughbred of sin.
It is considered one of the greatest things on the internet. It can be found at www.drhorrible.com.