It has been 15 years since Buffy the Vampire Slayer ended, but fans new and old alike continue to discover the numerous easter eggs hidden throughout the series. The writers behind Buffy wove together intriguing and emotional plots, creating an entire world of magic, demons, and girl power. The series excellently raised the bar for all the supernatural dramas that followed, in no small part because of how well planned out in advance its story arcs were. The other benefit of this is that it enabled the writers to foreshadow important events and leave teasers and easter eggs more strategically than most shows. Some of them are so well buried or obscure that they only make sense during a second viewing (or third or fourth).

It seems that each time we watch an episode there is something new we didn’t see before. While some easter eggs are tied in to key plot points, others are purely nods to the fans, like the reasoning behind the name for the Polgara demon (it was a fan’s screen name). Still easter eggs are there just to test how well you are paying attention. Again, we don’t want to give it all away here, but check out the part below about the writing on Tara’s back in “Restless.” Who knew?! There is a lot of fun to be had in watching Buffy whether it is for the first time or the one-hundredth. Discovering easter eggs like these 20 make the experience that much more exciting.

20 THE GENTLEMEN'S REVELATIONS

In “Hush” nobody was vocally offering up any easter eggs, that does not mean there were none. When Buffy and Willow walk through Sunnydale after everyone loses their voices, they pass a group of people holding an outdoor mass. The sign indicating the scripture reading reads Revelation 15:1. An easy thing to look over, this is actually a cool easter egg.

The featured Bible verse reads, “I saw in heaven another great and marvelous sign: seven angels with the seven last plagues -- last, because with them God's wrath is completed.” This is fitting as the big bads are the seven demonic Gentlemen who, in a miraculous feat, steal all the townspeople’s voices and wreak havoc like a plague themselves, going after people’s hearts.

19 100 APOCALYPSES

Giles and Buffy in Buffy the Vampire Slayer

In the season five finale “The Gift,” which was originally intended to be the series finale, Buffy and Giles reflect on their past adventures while in the training room in the back of the Magic Box. During the conversation, a little easter egg was slipped in.

As they stroll down memory lane, Buffy says to Giles, "This is how many apocalypses for us now?" He says that is has been at least six, but that it felt like a hundred. This is a reference to the fact that “The Gift” was the series’ 100th episode. Giles is also right about the actual number of apocalypses -- they had averted six over five years.

18 THE PINK RANGER CONNECTION

Go, go Buffy Ranger? Kinda. In season two’s “What’s My Line?: Part 2,” Buffy tells Kendra to “'Back off, Pink Ranger.' It may have seemed like an odd reference for Buffy to make, but the nonsensical comments are often the ripest with meaning. In this case, it is a reference to Buffy’s stunt double at the time.

Sophia Crawford was Sarah Michelle Gellar’s Buffy stunt double for 44 episodes from 1998 to 2000. She had previously been the stunt double for the original Pink Ranger, played by Amy Jo Johnson, in Mighty Morphin Power Rangers. Her husband, Jeff Pruitt, was also the stunt coordinator for both shows.

17 THE RELATIONSHIP BETWEEN CECILY AND HALFREK

Doesn’t Halfrek look just like Cecily? You remember Cecily; in “Fool for Love” a pre-Spike William confessed his love to her in 1880s London. He embarrassed Cecily and himself with his feelings and poetry. In response, she told him he’s beneath her. Skip to season six and we meet Anya’s vengeance demon coworker Halfrek who looks exactly like Cecily. Coincidence?

Actors with smaller roles are often recycled in TV shows, and many assumed that’s what happened here. Others argued Halfrek was Cecily. In “Older and Far Away," Halfrek and Spike finally cross paths and appear to recognize each other. She even calls him William. This was a nod to all the Cecily-Halfrek fan theories. Joss Whedon later confirmed they were the same person.

16 WILLOW IS A MASTERMIND

Alyson Hannigan as Dark Willow in Grave

Joss Whedon is known for planning elements of his story arc years in advance. Willow turning evil is an example of this. Though it didn’t occur until season six, the general idea of Dark Willow had been planned as early as season three. Perhaps it was on Joss’ mind even before that.

In the season two episode “Phases,” Larry says to Oz about Willow, "That little innocent schoolgirl thing is just an act, right?" Oz jokingly responds, "Yeah. Yeah, she's actually an evil mastermind. Three seasons later, he wouldn't be wrong. Willow was not only the true big bad of the season, but she quickly conjured up a master plan to destroy the world by reviving the apocalyptic power of the demon Proserpexa’s effigy.

15 ONE HELLMOUTH OF A MAP

Most Buffy fans know that the Sunnydale Hellmouth is not the world’s only one. There is mention in both season three’s “The Wish” and the series finale “Chosen” of another Hellmouth in Cleveland. Though we never hear more of it, it turns out there are several across the globe, at least according to an easter egg map located at the Watcher’s Council headquarters.

In the episode “Never Leave Me,” there is a large map of the world’s Hellmouths hiding in plain sight. You can see it near Quentin Travers and it's a fun easter egg for the quickest of fans. It also indicated that even though Buffy closed the Sunnydale Hellmouth, she and the new slayer population still have miles to go before they sleep.

14 A WORLD OF NOTHING BUT SHRIMP

What is this world with nothing but shrimp? For starters, it's a pretty funny easter egg that appears multiple times. When Anya explains the concept of infinite universes with endless possibilities in season four’s “Superstar,” she says, “There could be a world without shrimp, or a world with nothing but shrimp.” Who knew this world would come up again after she made her point.

Anya again mentions the world of shrimp in season five when she is explaining multiple universes again. The idea even jumps shows, coming up as an easter egg in Angel. During the season five episode “Underneath,” the demon Illyria says that she has been to a world with nothing but shrimp that she mentions she quickly grew tired of.

13 THE WRITING ON HER BACK

Willow Rosenberg and Tara Maclay spend time together outside in Buffy Season 4

The season four finale “Restless” was layered with subtext, abstract scenes, foreshadowing, and nonsensical elements like the Cheese Man. While most of these clues and hints have been picked apart by fans, there is one obscure easter egg almost everyone missed. The foreign language Willow is writing on Tara’s back was never explained in the episode, but it was actually a love poem written by the Greek poet Sappho of Lesbos.

Sappho is known for the gay feelings expressed in her work and the term for a female relationship comes from her home, the Greek island of Lesbos. While it is no revelation that Tara and Willow were romantically involved by that point, this easter egg still makes for a fun reference.

12 THE MANY MEANINGS OF MOLOCK'S NAME

When Moloch appeared in season one’s “I, Robot...You, Jane” he was pretty much your average monster of the week. Often there is no meaning behind the demons' names, never mind an etymological one. The Polgara demon was affectionately given its name by writer David Fury in honor of an active fan on the Buffy discussion boards. Moloch’s name is a bit more tied to his character, though.

A traditional Hebrew name for demons, Moloch, also called Moloch the Corruptor, is an easter egg geared towards the computer savvy. The C-based languages have a function named malloc, which is short for Memory Allocate. Given that Moloch became a robot and the episode is technology and internet heavy in content, it seemed fitting.

11 DAWN IS COMING

Dawn’s arrival in season five came at the end of a long trail of easter eggs. The hints are subtle, but in hindsight they add up quickly. When Buffy goes to drop Faith in “Graduation Day,” Faith says, "Look at you, all dressed up in big sister's clothes." In the shared dream between the two in the next episode, Faith mentions Little Miss Muffet, starting a reoccurring reference to Dawn.

During a dream sequence in season four’s “This Year’s Girl” Faith tells Buffy that “little sis is coming.” Also, in season four, Tara tells Buffy in her “Restless” dream to “be back before dawn.” When she wakes, Buffy stops and looks in the room that would become Dawn's when she appeared in the next episode.

10 COUNTDOWN TO THE END

Buffy the Vampire Slayer The Gift

Buffy’s end in the season five finale was both tragic and heroic. By jumping into the portal, she saved Dawn and the world. It seemed so sudden when it happened, but her demise had actually been ramping up via easter eggs as far back as season three.

In the “Graduation Day, Part 2” dream sequence, Faith says to Buffy, "Miles to go, little Miss Muffet, counting down from 7-3-0." The 730 is the number of days in two years, which is when Buffy would pass away. The phrase “miles to go” comes from Robert Frost's poem about moving on, "Stopping By the Woods on a Snowy Evening." The First Slayer mentioned it more directly, telling Buffy in the season five episode “Intervention” that passing on was her gift.

9 NERF HERDER'S SUBTLE SHOW

Nerf Herder is famously known for writing the Buffy theme, but did they ever play at the Bronze? Most viewers would say no but look back at the season seven episode “Empty Places” and you’ll find they performed right under viewer’s noses as one of the series’ last easter eggs.

When the potential slayers are out at the Bronze, an unnamed band performs on stage. Their name is never mentioned but Dawn alludes to their significance. When Kennedy says, “What kind of band plays during an apocalypse?” Dawn replies, “I think this band might actually be one of the signs.” Appearing in the fourth to last episode of the series, they were also the last band to play at the Bronze.

8 BUFFY JOKINGLY PREDICTS TRAGEDY

Sarah Michelle Gellar as Buffy in The Body

The end of Buffy’s mother Joyce is arguably the most heartbreaking of the series. The only thing more painful is realizing that a year prior an easter egg had been laid, foretelling her passing. In “The Freshman,” when buying textbooks, Buffy offhandedly says, “I can’t wait till mom gets the bill for these books. I hope it’s a funny aneurysm.” In hindsight it is so on the nose it hurts. The following season, Joyce suffered an aneurysm.

Buffy’s comment was quite calculated. It came a year after actress Kristine Sutherland told Joss Whedon she was going to leave the show. He told her that he was going to write off her character in a few seasons and needed her to maintain some presence until then.

7 LIKE WATCHER, LIKE VAMPIRE

During Xander’s dream in “Restless,” he sees Buffy, Giles, and Spike in a park. Spike, out in daylight, is wearing a tweed jacket reminiscent of Giles’ standard attire earlier in the series. Giles says to Xander, “"Spike's like a son to me." In the season six episode “Tabula Rasa,” Giles and Spike come to briefly believe this.

When everyone woke up after losing their memories because of Willow’s spell-gone-awry, Spike finds he is wearing the same tweed jacket from the dream. As the gang tries to figure out who they really are, he and Giles determine from their clothes and British accents that they must be father and son.

6 WILLOW IS BORED

It was fun seeing Willow’s vampire doppelgänger return again in season three. As Willow notes, she and her vampire self share some stark differences -- at least at the moment. "I'm so evil... and I think I'm kinda gay," she observes. Vampire Willow also uses her memorable catch phrase, “Bored now.” Both this phrase and Willow’s observations were both easter eggs.

Joss Whedon had intended early on to make either Xander or Willow gay. In season four, Willow comes out as gay and begins a romantic relationship with Tara. In season six, she becomes eviler than her doppelgänger could have ever hoped to be. She uses her alternate timeline self’s signature “Bored now” a moment before finally getting rid of Warren.

5 BUFFY BREAKS THE FOURTH WALL

The season six episode “Once More, with Feeling” was original and groundbreaking in many ways. There was singing, dancing, and Xander inexplicably getting away with committing crimes. And who can forget Buffy’s big confession to the Scooby Gang that she had been in heaven, not hell, when they pulled her out. There was a lot to take in but buried among the songs and drama were a few easter eggs. One of these included Buffy breaking the fourth wall.

When Buffy learns that the demon Sweet has kidnapped Dawn, she says "So Dawn's in trouble, must be Tuesday." Forget Monday, Tuesday is the most hellish day of the week for the Slayerettes since the series almost always aired on Tuesday nights.

4 WACKY NIGHTMARES

Willow actress Alyson Hannigan was not big on singing in “Once More, with Feeling,” but one of her few solo lines offers up a fun throwback easter egg. As the gang sings about their theories on what is going on Willow says, "I've got a theory, some kid is dreaming and we're all stuck inside his wacky Broadway nightmare." It is not only a plausible theory, but it happened once.

In the season one episode “Nightmares,” a comatose child named Billy turns Sunnydale’s residents’ nightmares into reality. In Willow’s instance this also includes singing when she finds herself on stage tasked with performing Madam Butterfly, a horrifying prospect for the character and the actress.

3 A GLORIOUS ACCUSATION 

When Glory brain-sucked Tara in season five it seemed to leave her with some sort of second sight. During the “The Gift,” Tara inexplicably knows she has to be at Glory’s tower and she even knows how to get there without ever having been. Most chillingly, she accurately accuses Giles of a fateful crime.

As the Scooby Gang leaves the Magic Box to go face Glory, they let Tara go first so they can follow her to the unknown location. As she passes Giles, the abstract and incoherently mumbling Tara stops, points at Giles, and yells something ominous. This easter egg didn’t take long to be explained -- later in the episode, Giles would end Glory’s host body, Ben, to keep the hell god from returning.

2 WARREN'S SKIN TROUBLES

Sometimes things are intentionally foreshadowed and sometimes they just work out by chance. This instance involving Warren of the Evil Trio is definitely the former. In the episode “Villains,” Warren goes to Rack to get magical protection against Buffy, who he believes is coming after him for shooting her. He doesn’t know he shot Tara also, but Rack can sense Willow’s rage.

Rack tells Warren that Buffy is the least of his problems to which Warren quips, “You're right. Let's talk about my skin troubles. You know, I'd say on the scale of problems, that she ranks!” In a twist of fate, Warren does suffer some skin troubles later in the episode when Dark Willow catches up to him and...well, you know the rest.

1 BUFFY'S EXPIRATION DATE

The return of Faith in “This Year’s Girl” and “Who Are You” was one of the highlights of season four and as with any pertinent Buffy episode, it was layered with foreshadowing and easter eggs. Some of them are well known, but this one would only be caught by the most eagle-eyed viewers while rewatching the episode after the end of season five.

While she is in Buffy’s body, Faith takes Joyce’s credit card to book a one-way flight out of Sunnydale and to a new life. While she is booking the flight on the phone, she is asked to provide the card’s expiration date. She replies that that is 5/01. May 2001 is when Buffy passed on in “The Gift.”