Yacht Club Games has given a release date of September 17th for the first free DLC, Plague of Shadows, for Shovel Knight. This DLC introduces Plague Knight, as a playable character, and a new Challenge Mode. This expansion has been in the works for a while and was one of the stretch goals from the Kickstarter campaign. Also Plague Knight is one of many boss characters that is being turned into a playable character.
To be able to play as Plague Knight you will have to have beaten the original story of Shovel Knight first. Also if you just want to start playing as Plague Knight immediately or have switched platforms Yacht Club Games will issue out a code for that. Shovel Knight is out now on Xbox One, PlayStation 3, PlayStation 4, PS Vita, Wii U, 3DS, and PC. Each version has its own exclusives from Battletoads on the Xbox One version to new modes with the Shovel Knight Amiibo on Wii U/3DS.