Top Undertale Cameos in Deltarune: From Fan Favorites to Story Shakers

The arrival of Deltarune, the latest project from celebrated indie developer Toby Fox, sent waves of excitement through the gaming community. With its innovative RPG mechanics, captivating narrative, endearing cast, and beautiful soundtrack, it quickly captured hearts. For fans of Fox's previous masterpiece, Undertale, the delight was twofold. They discovered that Deltarune was not merely a spiritual successor but a new adventure populated with familiar faces. While the creator has clarified that the two games exist in separate worlds, this hasn't prevented a delightful influx of cameos from iconic Undertale characters, primarily as residents of the Light World's Hometown. Many of these appearances are fun, small nods, but to the surprise of many, several have woven themselves into the very fabric of Deltarune's evolving story, especially as the chapters have progressed into their third and fourth installments. The game is rich with these fascinating crossovers, but some stand out as particularly noteworthy for their impact, humor, or unexpected significance.

😺 Temmie: The Adorable Classmate

In Undertale, the Temmie species—small, cat-like monsters with delightfully broken speech patterns—became an instant fan favorite, thanks to their absurd humor and cute designs. They serve as the avatar for the game's main artist, Temmie Chang, and rose to unofficial mascot status. Deltarune brings one of these peculiar creatures directly into Kris's classroom. This Temmie, simply named Temmie, maintains all the charming linguistic quirks and silly humor that fans adore. While she can't be engaged in battle as a Darkner enemy, she provides one of Chapter 1's funniest moments: when Kris asks to be her partner for a school project, she proudly declares she already has one—an egg. It's a perfect, low-stakes cameo that preserves the character's essence in a new, peaceful context.

🐱 Catty & Bratty: From Best Friends to Feuding Neighbors

One of the most interesting aspects of these cameos is seeing how character dynamics shift between worlds. In Undertale, Catty and Bratty were inseparable best friends and gossipy vendors. In Deltarune, however, they are neighbors who consistently talk badly about each other whenever Kris is around, clearly indicating they are not friends in this reality. Yet, as the player persistently interacts with them across chapters, subtle hints emerge. They slowly realize they share numerous interests during their chance encounters, suggesting a budding connection. This clever twist sets up a potential arc where these two memorable NPCs might rediscover their friendship, mirroring a theme of connection that runs through both games.

👩‍🏫 Alphys: The Caring Teacher

Alphys, the Royal Scientist of the Underground, was a cornerstone of Undertale's plot, involved with human souls, Mettaton, and Flowey. Her nerdy personality and relationship with Undyne made her deeply relatable. Her role in Deltarune is, for now, more subdued but wonderfully fitting. She is a school teacher in Hometown, retaining her dorky charm and evident crush on Undyne. More importantly, she genuinely cares for her students, including the troublemaker Susie. While her part has been smaller, cryptic dialogue about the town's mysterious shelter strongly hints that her scientific knowledge could propel her into a much larger role in the story's future chapters.

💀 Sans: The Mysterious New Neighbor

No character is more synonymous with Undertale than Sans, the laid-back skeleton secretly holding immense power and meta-awareness. His appearance at the end of Deltarune's first chapter was a monumental moment for fans. In Hometown, he has moved in with his brother Papyrus and quickly befriended Kris's mother, Toriel, due to their shared love of puns. This leads to one of Chapter 4's most bizarre and memorable scenes: Sans and Toriel sharing a dance in the Dreemurr household. His brief, awkward interaction with Toriel's ex-husband, Asgore, also implies a deeper awareness of the family's tensions. While his personality remains consistent, his integration into the Dreemurr family drama has been a shocking and fascinating development for the community.

Toriel: A Grounded and Imperfect Mother

Toriel, the loving guardian of the Ruins in Undertale, returns as Kris's mother in Deltarune. She shares her predecessor's warmth, pun-loving nature, and disdain for Asgore. However, this version is more grounded and humanly flawed. She is navigating a complicated divorce while trying to build a new social life, which explains her quick friendship with Sans. Her importance to the plot was heavily underscored in Chapter 3 when the Roaring Knight attempted to kidnap her, strongly implying she holds a key—potentially literally, for the shelter's door—to the overarching mystery.

👑 Asgore: The Tragic Figure in a New Light

King Asgore Dreemurr's story in Undertale was one of profound tragedy, driven by loss and a desperate, morally grey mission. In Deltarune, the surface-level dynamic is similar: Toriel has left him. He appears as a kind, gentle father and flower vendor, beloved by the town and desperately trying to win back Toriel's affection, making her coldness seem initially unfair. However, the narrative slowly drips with implication that Asgore has done something truly terrible to justify Toriel's resentment. Even more intriguing are hints that he might be collaborating with the story's central antagonist, the Roaring Knight. This complex setup has led many to theorize that the beloved king could transform into a major antagonist in Chapter 5 and beyond.

Undyne: From Silly Cop to Returning Hero

The contrast between the two versions of Undyne is perhaps the most dramatic. In Undertale, she is the fierce, passionate leader of the Royal Guard. In Hometown, she is a police officer with little to do, often seen engaging in over-the-top, comical antics like flexing in traffic. She even laughs off Kris's warnings about the Dark Worlds. This makes her moment in Chapter 3 all the more spectacular. Appearing within the TV World, she unleashes her iconic magic spears to save the main party from the Roaring Knight, instantly transforming back into the brave hero fans remember. This heroic return was a major story highlight, tragically cut short when she was immediately kidnapped by the villain, setting up a likely rescue mission in future chapters.

🔨 Gerson Boom: From Obscure Vendor to Legendary Figure

Gerson's cameo is the ultimate example of a deep-cut character being elevated to legendary status. In Undertale, he was a wise but easily overlooked turtle monster vendor. Deltarune reimagines him as Gerson Boom, a deceased historian from Hometown's past who knew secrets of the Dark World. In Chapter 4, the party meets him reincarnated as a Darkner in the Church. He initially seems like a feeble old man but soon reveals immense wisdom and strength, teaching Susie healing magic and aiding in a pivotal battle. Furthermore, he stars in an extra-hard secret boss fight, transforming into his "Hammer of Justice" form to test Susie for a legendary weapon. This transformation from background NPC to pivotal, powerful figure is one of Deltarune's most brilliant and surprising narrative choices.

Character	Undertale Role	Deltarune Role	Key Difference / Impact
Temmie	Adorable monster / mascot	Kris's classmate	Maintains humor in a peaceful setting; no battles.
Catty & Bratty	Best friend vendors	Feuding neighbors	Dynamic flipped; potential friendship arc hinted.
Alphys	Royal Scientist	School Teacher	Retains personality; hinted future importance via shelter knowledge.
Sans	Powerful, meta-aware skeleton	Toriel's new friend	Integrated into family drama; awareness of tensions.
Toriel	Guardian / Former Queen	Kris's mother	More flawed, dealing with divorce; key kidnapping target.
Asgore	Tragic King	Flower vendor / ex-husband	Seemingly kind but implied dark past; potential antagonist.
Undyne	Royal Guard Leader	Town Police Officer	Comic relief turned heroic savior; kidnapped after climax.
Gerson	Old vendor / historian	Legendary Darkner warrior	Elevated from obscurity to wise mentor and secret boss.

These cameos do more than just wink at the audience; they enrich Deltarune's world, creating layers of familiarity, surprise, and narrative potential. They show Toby Fox's mastery in re-contextualizing his own creations, allowing them to grow and serve new purposes in a separate but connected tapestry. As the story continues to unfold toward its conclusion, the roles of these familiar faces will undoubtedly remain a central point of fascination and theory for the fanbase.

As detailed in Destructoid, the evolution of beloved characters across game universes is a recurring theme that resonates with fans. Destructoid's features on indie RPGs like Deltarune emphasize how reimagined roles and unexpected cameos not only serve as nostalgic callbacks but also deepen the narrative complexity, keeping both new and returning players engaged as the story unfolds.