Melissa Joan Hart Remembers Sabrina the Teenage Witch Costar Martin Mull After His Death: 'Such Fond Memories'

Melissa Joan Hart is paying tribute to her former Sabrina the Teenage Witch costar and friend, Martin Mull.

Mull's daughter, Maggie Mull, announced the news of the actor's death in a touching Instagram post on Friday, June 28. He was 80.

Hart, 48, later reflected on her memories with Mull via Instagram. He appeared in over 70 episodes of the Hart-led sitcom as Principal Willard Kraft from 1997 to 2000.

Looking back at their off-camera bond, Hart posted a throwback photo of her and Mull posing in costume together on set.

"Rest in Peace my friend. The incredible #MartinMull (Principal Kraft) has left us for his eternal rest," she began in the caption, adding, "I have such fond memories of working with him and being in awe of his huge body of work which before #SabrinaTheTeemageWitch included #Roseanne and #MrMom as the projects I knew him from."

She saluted Mull for his appearances on "huge shows as well as features and animation" following his time on Sabrina.

Mull also appeared and starred in shows such as Two and a Half Men, Arrested Development, The Ranch and The Cool Kids. He earned an Emmy nomination for his guest role on Veep in 2016. His film credits include Clue, Far Out Man and Mrs. Doubtfire. Most recently, he had guest appearances in Not Dead Yet, Grace and Frankie and The Afterparty.

In her Instagram tribute, Hart shared how Mull explained why he took so many roles.

"He once told me that he takes every job he's offered just in case the train comes to an end, which in this business tends to halt quickly," wrote Hart. "He was an artist who liked to paint and build things with his hands, a musician and a wonderful man who i am better for knowing. "

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The actress ended by stating that the world is better thanks to Mull.

"He will be missed but this world has benefited from his being here," she wrote. "My deepest sympathies to his family and friends. I will continue to cherish the Martin Mull art work hanging in my home!"

Hart and Mull's costar in Sabrina the Teenage Witch, Jenna Leigh Green — who played Libby Chessler on the show — also posted a heartfelt tribute to the late actor.

Green shared a funny GIF of a scene where Mull's character pretended to play a tiny violin for Libby, with his lines from the show, "Here's the world's smallest violin playing the world's saddest song just for you," written across.

"He was hilarious. He was kind. He was generous. And he was one hell of a scene partner for a young girl just starting out and eager to learn how to be a comedian," she began her caption.

Green continued, "The world is a little bit dimmer today. Rest easy dear, sweet Martin! 💔 #martinmull #mrkraft #sabrinatheteenagewitch."

In the comment section, Hart shared a nod to the GIF with a sweet message. "The biggest violin plays in the heavens tonight! ❤️," she wrote.