The actress' children revealed she died after a short battle with cancer. She was 71.
Kirstie Alley is being remembered by her Veronica's Closet co-star, Kathy Najimy, as "hilarious, talented beyond belief, and generous and loyal" and as an actress whose eccentric self was unparalleled in Hollywood.
In a lengthy statement shared with ET, the 65-year-old Hocus Pocus star recalled the first time she met the Cheers star and the wild adventures they embarked on, which included a lot of laughing and plenty of misbehaving.
"Heart heavy. I loved Kirstie Alley. We first met in a van on the way to shoot an all-women film in the desert," Najimy's statement began. "She was one of the most beautiful beings I had ever seen. And hilarious. And the desert was hot and dirty. And I was pregnant. And she had no filters and made me laugh. And that began our relationship."
The duo would later team up for the NBC sitcom Veronica's Closet, which aired for three seasons from 1997 to 2000. The sitcom, created by Friends creators David Crane and Marta Kauffman, starred Alley as Veronica "Ronnie" Chase, the owner of a lingerie company who dumps her cheating husband and embraces the single life. Najimy played her best friend, Olive Massery, who is also the chief financial officer for Veronica's lingerie company.
"We acted together for 3 years on the series Veronica's Closet," the statement continues. "And many fun 'kirstie-ish' projects, and wild birthday performances and picking her kids up and Christmas and cake decorating contests and all of it. Kirstie was first and foremost: FUN. AND ALWAYS WAS LOOKING FOR MORE FUN."
Najimy added, "We've seen 'Hollywood types' try to be eccentric, but they'll never match the true original, authentic, eccentric that is Kirstie. She had pet lemurs in her basement. She had freezers full of Jenny Craig. She built arbors, covered in flowers, inside her living room for dinners."
The actress also recalled how once, while in the middle of filming an episode of Veronica's Closet, "She grabbed me and said 'A-ee,' LET"S GO! (yeah, she called 'A-ee,' that's a longer story). Her driver took us to the Valley and we Christmas shopped until the first [assistant director] found us amongst the tinsel."
Najimy also recalled a trip to the swap meet "and I saw these huge antique painted 'Santa and Reindeers.' She caught me eyeing them- and the next day a truck pulled up and installed it on our lawn."
Alley, who died Monday after a short battle with cancer, is also being remembered for her immense talent and being her true self.
"Acting with her was some kind of free flowing dream. Nothing was off limits," Najimy said. "We mostly misbehaved and laughed. We went head to head about politics, religion, feminism, (I think it's hilarious she thought my 'quest to get our set at NBC to recycle' was so Liberal!). But again, mostly laughed."
Najimy, who shares 25-year-old daughter Samia Finnerty with husband Dan Finnerty, said one of the biggest joys they had came when they talked about their kids.
"She called Samia- 'Spammy'!" Najimy recalled. "Kirstie delightfully dedicated her life and love to her kids: Lily and True."
From "wild trips, egg hunts, crazy waterfall games in the pool," Najimy said "nothing was ordinary, nothing was mellow. EVERYTHING WAS FUN AND IGNITING AND ECCENTRIC. Kirstie was all of those things."
She added, "Hilarious, talented beyond belief, and generous and loyal. When we acted, it was a wild wash of fun. Pretty much everything she did was a wild wash of fun. My heart to True and Lily and their families. I regret I haven't said I love you in the past years. I love you."
Following Alley's death, the acting world reacted to the tragic news. Ted Danson and John Travolta were among the many celebrities who paid tribute to Alley, whose rep later confirmed was battling colon cancer.