Legends of Tomorrow: Who is Rex Tyler, AKA Hourman?

Tonight's episode of DC's Legends of Tomorrow, titled "Legendary," introduced a game-changing development in the final moments of the episode.

For about a month now, there have been reports that a caped hero would be introduced in tonight's episode, and that his mysterious agenda would drive much of the second season.

When we got to meet him, he arrived on board a trashed version of The Waverider, telling the team that Mick Rory had sent him to their time and place.

"I'm Rex Tyler," he said. "I'm a member of the Justice Society of America."

So...who is Rex Tyler?

He's a Golden Age superhero better known as Hourman.

Tyler has a number of superhuman abilities, like enhanced strength, reflexes, and healing -- but only for an hour at a time. His abilities are given to him by Miraclo, a drug he designed himself.

There is an Hourman legacy including Rex's son Rick and an android from the 853rd Century programmed to act as a member of the Tyler family. The android, at a point in the past, presented Rex with an hourglass infused with tachyons -- time in its most basic form -- and that hourglass would become part of both his and Rick's costumes. Said hourglass has been seen on board the Waverider on previous episodes of DC's Legends of Tomorrow.

In late 2013, The CW was developing a TV series based on Hourman, but in that case he had the psychic ability to see an hour into the future and would use that ability to prevent crimes before they happened.