Weeks after Perry died of a stroke at age 52, Swanson, 49, tweeted a throwback photo of the pair in tribute of her friend and fellow actor.
“For #FlashbackFriday I wanted to share this photo of Luke and I goofing off on the set of Buffy,” wrote Swanson, who starred on Buffy the Vampire Slayer opposite Perry in 1992.
In the comedic black-and-white photo, both Swanson and Perry had rubber lips and fangs in their mouths.
“Always the committed actor, he makes the perfect face for the character in the moment,” said Swanson.
She concluded, “I miss you so much my Buddy. I love you. #LukePerry.”
Perry was hospitalized after suffering a stroke on Feb. 27 after paramedics were dispatched to his home in Sherman Oaks, California. A source told PEOPLE he never regained consciousness.
The actor, who starred as Dylan McKay on Beverly Hills, 90210, remained “under observation” for five days, but died on Monday, March 4.
“Actor Luke Perry, 52, passed away today after suffering a massive stroke,” read a statement from Perry’s rep. “He was surrounded by his children Jack and Sophie, fiancé Wendy Madison Bauer, ex-wife Minnie Sharp, mother Ann Bennett, step-father Steve Bennett, brother Tom Perry, sister Amy Coder, and other close family and friends. The family appreciates the outpouring of support and prayers that have been extended to Luke from around the world, and respectfully request privacy in this time of great mourning. No further details will be released at this time.”
Swanson is one of many Hollywood actors who celebrated Perry’s life and accomplishments after his death.
Ian Ziering was the first 90210 star to pay tribute, tweeting, “Dearest Luke, I will forever bask in the loving memories we’ve shared over the last thirty years. May your journey forward be enriched by the magnificent souls who have passed before you, just like you have done here, for those you leave behind.”
Jennie Garth released an exclusive statement to PEOPLE: “My heart is broken. He meant so much to so many. Such a very special person. I share my deep sadness with his family and all who loved him. Such a terrible loss.”
“I am in shock. Heartbroken. Devastated by the loss of my friend. I have so many memories with Luke that make me smile and that are forever imprinted on my heart and mind,” Shannen Doherty exclusively told PEOPLE.
Perry, who is survived by his two children, son Jack, 21, and daughter Sophie, 18, whom he shared with ex Rachel “Minnie” Sharp.
“Luke loved his family,” Doherty said. “He raved about his kids and how proud he was of them. He showed me videos of the often. They were his heart and for him, his biggest accomplishment.”