When you watch The Flash Season 1 Episode 17 online, you will see Mark Hamill reprise his role as the Trickster, something he originated on the 1990s version of the series when John Wesley Shipp, who plays Barry's father, Henry, played the titular role. Cool, right? Just how outrageous can he be after all this time? Pretty damn outrageous. More of Harrison Wells' backstory will also be revealed, and while it's not as cartoonish as the Trickster's, it might be more far out. Tarry not and watch The Flash online now!