The Arrowverse has been going strong for so long that it is easy to forget about the actors you saw on it. In most cases we’re talking about are those people who appeared in one or two episodes, so it’s understandable that they may have slipped your mind.

But there are a handful of actors who had big arcs on these shows and are still somehow forgotten. Everyone loves seeing a familiar face pop up on a series they enjoy. So even if you forgot about them, we’re ranking 10 actors who were in the Arrowverse that you might not remember.

Robert Knepper

Some actors are always cast in one kind of role. For Robert Knepper, that role just so happens to be the villain. He played major bad guys on shows like Heroes, Prison Break, and iZombie, and smaller antagonists on series like The Blacklist. Knepper was the bad guy in the Arrowverse as well.

He portrayed William Tockman, better known as the Clock King. Interestingly, Knepper made two appearances across two shows. First, he was in Season 2 of Arrow in “Time of Death,” and then he returned during Season 1 of The Flash for “Power Outage.” He was formidable both times.

Lynda Carter

Lynda Carter actually has a pretty notable role in the Arrowverse. On Supergirl, she is Olivia Marsdin, the President of the United States. As usual with that show, there’s more to it because Marsdin is also an alien from a planet called Durla. Carter is a highlight, but some newer fans may not realize just who she is.

Cody Rhodes

Pro wrestling is a form of acting, isn’t it? The people performing have to tell stories and play characters just like every other actor on television. That might be why Cody Rhodes fit in so well on Arrow. It all began in WWE, where Rhodes started a war of words with Arrow star Stephen Amell.

It led to a tag team match involving both men at SummerSlam 2015. Following that, Rhodes guest-starred in seven episodes of Arrow. His character, Derek Sampson, was known for peddling a drug called Stardust, which was an homage to a character he played in WWE.

Billy Zane

With Titanic being one of the biggest movies in cinema history, almost everyone knows who Billy Zane is. He famously played Rose’s fiancé, Caledon Hockley, the guy we all loved to hate. For the Arrowverse, he channeled the same type of character.

In DC’s Legends of Tomorrow, Zane starred in the Season 3 episode “Freakshow.” He played the role of the legendary P.T. Barnum, who owned the Roving Museum of Freaks and Hypnotic Hippodrome in the show. It was a fun performance and it reunited him with Titanic co-star Victor Garber.

Rutina Wesley

Rutina Wesley is most famous for her time playing Tara Thornton on HBO’s True Blood. But she’s been around for a while and has appeared in other popular shows like The Walking Dead, The Cleveland Show, and Arrow. You might not remember her from Arrow, as she only appeared in two episodes.

As Liza Warner, Wesley was introduced in Season 4’s “Beyond Redemption.” She was part of the anti-vigilante task force put together to combat the Green Arrow. Wesley returned for Season 5’s “The Sin-Eater,” where she teamed with Carrie Cutter and China White.

Mark Hamill

An argument could be made for Mark Hamill being the most famous entry on this list — playing Luke Skywalker will do that for someone’s career. Hamill is also known for delivering iconic work as the voice of the Joker in various mediums. But he came to the Arrowverse as another villain.

Hamill joined The Flash as the Trickster, James Jesse. That was notable because it was a character he played during the old 1990 The Flash TV series. The only reason Hamill doesn’t rank higher is that he is probably not as forgotten as some others due to his vast popularity.

Emily Kinney

We have another Walking Dead alum on the list. Emily Kinney was a much bigger piece of that show than Rutina Wesley, as the former played Beth Greene. Kinney has also nabbed major roles on Conviction and Masters of Sex. In the Arrowverse, she appeared on two shows.

First there was “All Star Team Up,” which was a first season episode of The Flash. Kinney played Brie Larvan, a former Mercury Labs employee who becomes known as the Bug-Eyed Bandit due to her ability to control a swarm of robotic bees. She returned for an episode of Arrow and has become a rival of Felicity Smoak.

Summer Glau

The fact that so many people forget about Summer Glau’s Arrowverse run is kind of a shame. Glau is a sci-fi dynamo. Just look at her work in Terminator: The Sarah Connor Chronicles, Firefly, The 4400, Dollhouse, or even a small role on Chuck. And it’s not like her time on Arrow was short-lived.

Summer Glau played Isabel Rochev in nine episodes during the outstanding Season 2. She went from a relatively minor supporting character to a possible love interest for Oliver to a cunning villain known as Ravager. Maybe Glau gets overlooked because Manu Bennett was so fantastic as Deathstroke at the same time.

Darren Criss

You almost can’t believe that Darren Criss appeared in the Arrowverse. Almost no one seems to remember it. Darren Criss is most known for his longstanding run on Glee, but he’s gone on to star in American Horror Story and American Crime Story in recent years.

His appearance on The Flash was perfect. As the Music Meister, he captured Barry Allen and Kara Danvers in a dream world where everything was a musical. It was one of the best Arrowverse crossover episodes in history. The reason it worked so well was probably that Criss, Grant Gustin, and Melissa Benoist all worked on Glee at one point.

Patrick J. Adams

Patrick J. Adams is the kind of guy who you have seen all over the place. The most notable spot is as a lead lawyer on USA Network’s Suits, but he’s also had roles on Orphan Black, Friday Night Lights, and Lost. His time in the Arrowverse was small but important.

Adams played Rex Tyler, who first showed up at the end of season one of DC’s Legends of Tomorrow. In this cameo, he arrived to warn the team of their death, which was coming up quickly. We were able to see Adams again a few episodes later when the Legends traveled to 1942 in “The Justice Society of America.”