Tonight’s Season 7 finale of DC’s Legends of Tomorrow was a big one for the long-running Arrowverse series. Not only did it, as previews had previously revealed, see the heroes go back on their retirement to time travel once again in an effort to save one of their own, but it also saw the introduction of a fan-favorite character into The CW‘s DC Comics-inspired series. As many fans suspected when the casting of Scrubs alum Donald Faison was announced earlier this year, Michael Jon Carter—better known as the hero Booster Gold—made his debut in “Knocked Down, Knocked Up” and the internet went wild.

Warning: spoilers for episode details of “Knocked Down, Knocked Up”, the Season 7 finale of DC’s Legends of Tomorrow.

The episode saw the Legends head back to World War I upon realizing that Gwyn had gone back to save Alun and had gotten himself killed in the process. Unfortunately for them, Alun’s death is a fixed point in the timeline, which means that there’s a fixer there keeping things in check. Booster—or Mike as he’s introduced initially—is that fixer. Viewers are first introduced to the character as he’s frozen time and is playing a bit of golf on the World War I battlefield, dressed in a very Booster Gold-themed golf ensemble. The episode ultimately confirms that Mike is indeed Booster Gold at the end of the episode when a time cop mistakenly calls him “Buster”, prompting a very direct correction.

In comics, Booster is a 25th century college football star who gambled away his future and was tossed out of the sport. While working as a night watchman at the Space Museum, Booster stole several artifacts from the heroic age of the 20th century and travelled back in time to become a superhero himself. While this week’s Season 7 finale only introduces us to the character—and with Season 8 of DC’s Legends of Tomorrow not yet confirmed—how the show will develop the fan-favorite Booster Gold is anyone’s guess. But for now, fans are just thrilled to see the character become part of the Arrowverse. You can check out a roundup of some of how fans have been reacting on Twitter and be sure to let us know your thoughts in the comment section as well.