The Chilling Adventures of Sabrina features the most Sabrina the Teenage Witch Easter eggs in season 4. While there are one or two references throughout the series, the last season has the majority of throwbacks in the penultimate episode. The Chilling Adventures of Sabrina honoring Sabrina the Teenage Witch in its final installment isn't unexpected, but some of the references are more obvious than others.
Though both shows are based on the Archie comics, Netflix's The Chilling Adventures of Sabrina took a significantly darker, less family-friendly route than its beloved '90s predecessor. The former deals with a coven of witches who worship Satan, for instance, and the latter has a secular Witches' Council. They are vastly different in tone, but season 4 of The Chilling Adventures of Sabrina does contain some obvious and obscure nods to the original sitcom, as it does to some horror movie classics.
Almost all of the Easter eggs appear in season 4, episode 7, "The Endless." Sabrina Morningstar travels via mirror to an alternate dimension to keep another Eldtrich Terror from destroying her current reality. What she arrives in is an endless sitcom of her life, complete with canned laughter. The most obvious Easter eggs are her aunts, who in this parallel universe are played by Caroline Rhea and Beth Broderick, Sabrina the Teenage Witch's Aunt Hilda and Aunt Zelda. They live under the constant scrutiny of the self-proclaimed show's star and the 7th Eldritch Terror, Salem, the sitcom's talking cat puppet. Instead of Nick Bakay, the original voice actor, Salem is voiced by Luke Cook, who also plays Lucifer. After a disastrous take, one of the crew members refers to Salem as "Mr. Saberhagen," which hearkens back to the sitcom and the comic book. Salem Saberhagen in the '90s show is a centuries-old witch who is sentenced to live as a cat for 100 years because he tried to take over the world. Salem often hilariously laments to the Spellmans about not achieving world domination. In The Chilling Adventures of Sabrina, he is merely Sabrina's familiar in her current reality.
In the episode Sabrina is filming, she dresses up like a cockroach and asks Harvey for a true love kiss to turn her human again. This is most likely a nod to an episode in season 1 of Sabrina the Teenage Witch, when Sabrina and Harvey's first kiss turns him into a frog. Sabrina passes a true love test to prove her feelings and must kiss the frog to bring Harvey back. The use of Sabrina's mirror as a wormhole also directly parallels another episode of the sitcom where Sabrina's mirror alter ego invites her into her world. Sabrina goes through the mirror, but ends up trapping herself.
Towards the end of "The Endless," Sabrina worries about the Void ending the parallel dimension. Hilda comments that most television shows add something huge, like a death, marriage, natural disaster, or a trip to Hawaii to revitalize the audience's interest. In Sabrina the Teenage Witch, the Spellmans do visit Hawaii for a family reunion and Sabrina learns the family secret that all Spellmans have an evil twin. This idea of doubles also comes into play in Chilling Adventures, since a time paradox creates a past and present Sabrina which allows her to live separate lives. In terms of marriage, both versions of Hilda get married, as does Sabrina Morningstar at the beginning of season 4.
Apart from these easter eggs, The Chilling Adventures of Sabrina feature other minor references to the '90s sitcom in season 2. Sabrina switches out outfits in front of her mirror, like Sabrina does in the opening credits of Sabrina the Teenage Witch. She also scarfs down pancakes, mirroring '90s Sabrina's inherited addiction to them. Though Netflix's approach to Sabrina was decidedly a lot more mature and serious in tone, it did manage to weave in some memorable references to the original hit show.