The Character Everyone Forgets Jeffrey Dean Morgan Played In Grey's Anatomy

Before landing the role of Negan on AMC's horror drama "The Walking Dead," Jeffrey Dean Morgan was a journeyman actor whose face was familiar to thousands thanks to his regular appearances on the small and big screen.

Morgan is primarily known for his action roles. You're likely to remember him as John Winchester, pop to Dean and Sam on the long-running CW drama "Supernatural," or perhaps as the Sheriff in the popular cult comedy-horror film "Dead and Breakfast," or as the brutal vigilante known as the Comedian in the 2009 film version of "Watchmen." But the actor also has a softer side. He appeared in the romantic drama "P.S.: I Love You," and had a long-running arc on the ABC medical drama "Grey's Anatomy." 

His storyline was a real tearjerker that proved pretty popular with the show's fanbase. It involved a love story with a major member of the show's cast and his presence effected the show's story for many years after he left the show. Who did Morgan portray?

Morgan portrayed Denny Duquette, Jr., a heart transplant hopeful living with viral cardiomyopathy during "Grey's Anatomy" second and third seasons. He met and had immediate chemistry with Dr. Izzie Stevens (Katherine Heigl), but the hospital didn't have a heart for him and she was the one who had to tell him so, which put a slight damper on their hopes for romance. 

As Denny begins to go into heart failure, the doctors struggle to figure out a way to slow his cardiac rhythms down. He and Izzy spend more and more time together during this period, and come to know and like one another. When Denny's heart failure worsens, Izzy encourages him to get an LVAD, which will keep him in the hospital until a donor heart was found. 

Bedbound and suffering from shortness of breath, Denny considers getting a portable LVAD, which would at least let him move around the hospital. He and Izzie clash over the idea, but he ultimately gets the device. Unfortunately, the portable LVAD only allows Denny limited freedom, and he collapses in a hospital stairwell when its batteries go dead. By the time a heart arrives, Izzie is too emotionally attached to Denny to perform his transplant surgery herself. When the donor falls through, Izzie cuts the lines to Denny's LVAD to make him look sick enough to get an emergency heart. As the interns struggled to keep him alive, Denny and Izzie decide to get married.

Even though the heart is successfully transplanted into Denny's body, he dies anyway, due to a clot. In a tragic coda, Izzie is heartbroken and refuses to leave Denny's body until her ex, Alex Karev (Justin Chambers) physically removes her from his presence.

As any fan of "Grey's Anatomy" knows, just because a character's dead doesn't mean that they're gone. True to form, Denny — with Morgan still portraying the role — has popped up a few times since shuffling off that mortal coil.

It is Meredith who has a vision of Denny first. During the Season 3 episode "Drowning on Dry Land," she hears Denny's voice as she flatlines after nearly drowning. In the subsequent episode, "Some Kind of Miracle," she, her long-gone dog Doc, and Denny sit in a purgatory-like waiting room with Dylan Young (Kyle Chandler), as Meredith tries to choose between life and death itself.

But Izzie ends up being haunted by Denny on a much more frequent basis. In the immediate aftermath of Denny's death, Izzie learns that he'd left her millions of dollars via a verbal bequest left on his parent's answering machine. She establishes a memorial clinic in his name with the cash. But that doesn't stop visions of the man from haunting her throughout Season 5 (a story arc some fans believe went too far) as she treats Michael Norris (Tom Verica), the man who was supposed to get the heart she swiped for Denny. Tormented by these visitations, Izzie begs him to go so she can continue living in the present. But there's something far more sinister lying at the root of Izzy's troubles — cancer. She's been seeing Denny because she has tumors in her brain.

Though Izzy eventually beats cancer and moves on with Alex, she never forgets Denny.