This year marks two decades since first debuted on our small screens. Creator ' medical premiered to a relatively light fanfare before thanks to its ensemble cast, high-stakes hospital drama, and emotional stories that zig-zagged with enough flair to put soap operas to shame.

, the rotating staff of Grey Sloan Memorial has seen countless patients — and that's an excellent job opportunity for both up-and-coming actors and familiar names. , especially considering how many became household names after their appearances. Here are 10 actors who guest starred on Grey's Anatomy that you might have forgotten about, ranked.

One of the first onscreen roles for the trilogy and actress was none other than Grey's Anatomy circa 2006. , is admitted to Grey's Sloan under rather awkward circumstances. During her prom, Camille falls unconscious while having sex for the first time.

Although initially played for laughs, toward a darker truth — the incident means Camille's ovarian cancer has returned after three years in remission. Uncertain of what the future holds but determined to provide his niece with the best care, Richard throws a make-up prom for Camille. Thompson's role is small, all things considered, but she brings teenage determination, longing, and profound sadness to Camille.

, the legendary scream queen behind the franchise's main heroine, Sydney Prescott — not to mention the hit teen dramedy — breezes into Grey Sloan Memorial as Lizzle Shepherd, .

Lizzie's relationship with a newly pregnant Meredith Grey () isn't smooth sailing at first. Despite her marriage to Derek and their adopted child, Meredith hasn't reached out to Derek's side of the family. Lizzie, understandably, wants Meredith to make an effort to include her in her brother's life. The sisters-in-law develop a tentative rapport after Lizzie donates a nerve for Derek's injured hand and Meredith shares a picture from her ultrasound. Campbell's presence is immediately intimidating, making Lizzie a dynamic powerhouse of a professional woman.

Right before 's leading performance as Coach Eric Taylor in stole our hearts and won an Emmy Award, Chandler guest starred in one of Grey's most — which, considering 21 seasons, is saying something.

When a man with a live bomb inside his body enters the hospital, Meredith's intervention is the only thing standing between life and death for all of Grey Sloan. saves Meredith's life, but the bomb detonates while Dylan is transporting it from the hospital. Chandler's performance received an Emmy nomination for Outstanding Guest Actor in a Drama Series, and he returned for a cameo in Season 3 when Meredith has a near-death experience. Looking back on the episode with Entertainment Weekly, Rhimes said that once she cast Chandler, she "didn't want to explode [Dylan]."

Chandler isn't the only to emerge from the infamous bomb episodes. , best known at the time for her roles in , movies, and director ' , plays Hannah Davies, . When the terrified, exhausted girl can't go on, Meredith takes Hannah's place.

Like Chandler, Ricci's performance earned her a well-deserved nomination for Outstanding Guest Actress in a Drama Series at the 2006 Emmy Awards. It might be easy to judge Hannah for running away, but Ricci's raw, vulnerable performance reminds viewers that Hannah is just an inexperienced, scared person holding back instant death with her hands.

Although was many years into her career by the time she played a younger version of Meredith's mother, Ellis Grey, she was just on the cusp of her multiple breakthrough collaborations with on his anthology y.

Titled "The Time Warp," the episode flashes back to the circumstances surrounding , and how the relationship fell apart — namely, Ellis' determination to leave her husband for Richard clashing with Richard's refusal to divorce his wife, Adele. Paulson's scenes are almost blink-and-you'll-miss-it, but from her.

Before starring in Fox's series and director 's , award-winning actress, musician, and comedian played Sheryll Jeffries, and determined to be part of Cristina Yang's () clinical trial.

Cristina refuses to meet the volunteers or learn their circumstances, instead vetting her participants based just on their physical criteria. That leads Cristina to reject Sheryll without knowing her situation — a young woman facing motherhood all alone. Thankfully, Shane Ross () helps Sheryll deliver a healthy baby.

A decade before he starred as Clay Jensen in Netflix's drama series , was the precocious and chipper Ryan, the son of a cafeteria employee. , meaning he lacks ears but still has his hearing intact.

The boy and cheekily guilt trips him, as well as the other high-ranking staff, into approving him for free ear construction surgery. Not even Miranda Bailey () can resist his earnest approach — he trick-or-treats for his ears! — or his cheeky smile.

Yes, it's herself! Four years before 's period dramedy series took the streaming world by storm, Brosnahan played Brian Weston, through top surgery. Brian's transphobic father resists his son's transition, while Brian's girlfriend, Jess, unconditionally supports him.

Although casting Brosnahan, a cis woman, instead of a trans actor is a troublesome and stereotypical choice, her harrowing performance grounds the episode's empathetic severity and underscores the vital importance of keeping gender-affirming care accessible.

sneaked her way onto Grey's Anatomy in between and and years before Hulu's . Compared to the accolades Moss would later collect, her role as Nina Rogerson in the episode "My Favorite Mistake" is a traditional one-episode arc, but .

Nina tends to her mother Cathy () full-time, living in constant fear of her mother succumbing to her genetic illness. Although Nina would do anything for the mother she adores, she sacrifices much of her life for her caregiver role – and that's not a future her mother wants for her daughter.

Nothing strange (ahem) to see here, folks — just Stranger Things' breakout star Millie Bobby Brown. A sudden earthquake causes dozens of injuries across Seattle, but not everyone affected can make it to the hospital. Ruby (Brown), an 11-year-old girl, is trapped at home with her unconscious mother.

Grey Sloan dispatches emergency rescue services to reach the two, but until then, all Ruby can do is listen to Owen Hunt (Kevin McKidd) over the phone as he tells her how to intubate her mother. Ruby's mother survives thanks to both their efforts, and when the two meet face-to-face for the first time, their emotional hug speaks volumes.

Keep Reading: 'Grey’s Anatomy' Needs To Bring Back These Characters At Least Once