Deltarune: 10 Best Boss Themes, Ranked

1 hour ago 3

Published Jul 3, 2026, 2:10 PM EDT

Daniel Trock is a Contributor at DualShockers specializing in PC games, lists, and reviews. He has been writing professionally since 2018 and covering games since 2020, with previous work spanning guides, news, lists, and reviews across multiple publications.

Before joining DualShockers, Daniel contributed guides to GamerJournalist and lists to TheGamer. He currently covers tech topics for SlashGear and BGR. He holds a Bachelor’s Degree in Psychology from Marist College and a Master of Fine Arts in Creative and Professional Writing from Western Connecticut State University.

It’s no secret that, in addition to his game development chops, Toby Fox is an excellent game music composer. The man got to compose multiple tracks for a mainline Pokémon game, that’s how big of a deal he is. More often than not, we get to see Fox and his crew’s finest work on display during the boss fights of his games, Deltarune included.

Just about every boss, mini-boss, and especially secret boss in Deltarune is accompanied by a wholly unique theme song, each one reflective of the boss’s personality, the current story stakes, and in some cases, hidden thematic touches, often represented by recurring motifs in certain songs. All of them are awesome, and more than worth checking out the official soundtrack on Spotify for, but if you had to twist my arm and make me play favorites, I’d say these ten are the standouts, and in this particular order.

Spoilers for Deltarune Chapters 1-5 ahead!

10 A Dark Zone

Theme of Taking Too Long

Something I like about Deltarune, and this was also true for Undertale, is its ability to just pull a highly memorable character completely out of nowhere and immediately endear them to you over the course of a single boss fight. This is what happened with Jackenstein in Chapter 4, and it was helped in no small part by that fight’s unique song.

“A Dark Zone” starts out with a haunting, pixelated melody reminiscent of those from the NES-era Castlevania games. Jack’s trying to scare you, make himself seem more intimidating than he actually is. However, the song swiftly changes gears into a jaunty toe-tapper, aided by the little dancing pumpkin dudes at the bottom of the screen and the occasional saxophone break. It’s a clear indicator that, for all his attempts at being “SCAIRY,” Jack is just a big ol’ softy who doesn’t want to frighten anyone, and isn’t really capable of being scary outside just being loud.

9 Guardian

Theme of the Bump-in-the-Night

Ralsei describes the phenomenon of the Roaring, as well as the Titans that accompany it, as full-on forces of nature. They are destruction incarnate, they cannot be shown mercy or reasoned with, they exist only to destroy whatever’s unfortunate enough to be standing in front of them. This is made all-too-clear by the theme that plays when you finally confront a Titan in Chapter 4.

“Guardian” is the theme of the fully-unleashed Titan, meant to convey the sheer size and strength of this unspeakable entity. All throughout the song are pounding bass tracks that really drive home not just how literally large the Titan is, but how terrifying its presence is. In addition to that, you have organ melodies and chanting featuring the motifs of the Dark Sanctuary and “Don’t Forget,” all of which tie into the Titan’s major presence in the Legend of the Deltarune and the prophecy you’ve been seeing throughout Chapter 4.

8 Attack of the Killer Queen

Theme of Making Your Face into a Robot One

It’s something of a rule of thumb for games with unique boss battle themes that, if you’re fighting a character who’s supposed to be some manner of ruler or royal, the theme in question should sound appropriately haughty and domineering. Queen’s boss theme in Chapter 2 not only has that down, but adds a little extra theme of control for good measure.

Queen’s theme, “Attack of the Killer Queen,” plays while fighting both her and the wire-controlled Berdly near the end of the chapter. Naturally, it’s a faster-paced version of Queen’s usual royal organ theme, conveying her haughty demeanor and hostile intentions. What’s notable, though, is that the song also incorporates the motif of Berdly’s theme from his fight, reflecting the fact that he’s currently under Queen’s complete control. Rather amusingly, the two motifs actually mesh really well together, though I don’t think Queen would ever willingly admit to that.

7 It’s TV Time!

Theme of Primetime Cable

I had a lot of affection for my childhood CRT TV. It was the provider of shows, movies, games, and togetherness with my family. I imagine, if that old TV had an ego, it wouldn’t be dissimilar to Tenna’s in Chapter 3, though considering I threw that TV out ages ago, it would probably be similarly inclined to beat the snot out of me to the tune of all my old favorite media.

“It's TV Time” is Tenna’s theme for his boss battle near the end of Chapter 3. It’s a very boisterous, show-offy song, like Tenna is still trying to wring entertainment value out of this whole thing while you’re fighting him. Not only does it include motifs of Tenna’s other themes throughout the chapter, but in a really fun twist, it incorporates the distinctive soundfont of SNES games, particularly Turtles in Time. Nostalgia is Tenna’s whole shtick, so it’s quite thematically appropriate for his boss theme to incorporate music from a 30-year-old video game.

6 Cutie Mew Mew Magic

Theme of an Unexpected Hatsune Miku

Since the landmark release of Undertale, Toby Fox, his games, and their characters have become extremely ubiquitous in pop culture, to the point that most people can identify “MEGALOVANIA” in just a few notes. You know who else is really ubiquitous in pop culture with songs you can catch in a few notes? Hatsune Miku, of whom Chapter 5’s secret boss, Pink, is apparently a fan.

“Cutie Mew Mew Magic” is Pink’s theme, containing shades of her counterpart’s theme from Undertale, Mad Dummy, but with a distinct anime opening tinge, which fits her generally greater commitment to the bit of being an anime catgirl. Of course, the highlight is when Hatsune Miku suddenly chimes in, offering up a mix of English and Japanese lyrics just to really drive the thematic point home. During the bridge, in particular, it sounds a lot like an insert song from a magical girl anime, which Pink certainly fancies herself as the star of.

5 Flower Man

Theme of Jarona

The funny thing about thematic music in media is that, through many years of shared cultural experience and osmosis, we’ve naturally come to associate certain kinds of melodies with certain kinds of characters. This is why Flowery’s boss theme in Chapter 5 makes for an interesting subversion: it sounds less like a boss theme, and more like a protagonist’s theme.

Deltarune: Flowery Boss Fight Guide

Anything is possible with the power of friendship!

“Flower Man” is a very upbeat, triumphant track that reflects Flowery’s own perspective on your fight against him. From his side, he is the hero, the protagonist in this matter, trying to protect the world formed for the other flowers and the world they want to create to make Asgore happy. It’s his song because, from his perspective, he is definitively in the right of things, and wants to do right by his friends. In a similar vein to “Raise Up your Bat” from Chapter 3, the song also has lyrics, albeit inaudible ones presented at the top of the screen during the fight, which go further to demonstrate Flowery’s resolve to be a hero in his own right.

4 Hammer of Justice

Theme of Jolly Old Men

Speaking of heroes, the best kind of hero is one who can both fight for what’s right and have a good time doing it. In Chapter 4, Susie gets to meet that kind of hero in Gerson and share in his wisdom, though it’s when the two of them finally meet for a duel, and he takes up his moniker as the Hammer of Justice, that we really see what kind of fun he’s capable of.

The Hammer of Justice’s titular theme is a little different from many of the boss themes in Deltarune. It’s a battle theme, certainly, but it’s less of a “I’m going to kill you” theme and more of a “let’s have a good time” theme. It’s jaunty and light-hearted, especially with its backing banjo track, though it’s also still distinctly heroic, thanks to incorporating motifs from Undyne’s theme in Undertale. Gerson’s not trying to hurt Susie here, he just wants to see what she can handle, and how much she can grow as a hero in her own right in the process.

3 Big Shot

Theme of Excellent Deals

One of the oldest tricks employed by marketing firms is the catchy jingle, a quick, one-line riff or catchphrase that’s irritatingly easy to remember and forcefully sticks in your head forever. Rather fittingly, Spamton NEO’s boss fight theme has a line that nobody has ever managed to forget: “Now’s your chance to be a big shot!”

The aptly-named “Big Shot” is an evolution of Spamton’s other themes seen throughout Chapter 2, including the first time you fight him in an alleyway and the theme that plays in his store. Unlike in those themes, which are rather meandering and disjointed, like Spamton isn’t really paying you any mind, “Big Shot” is much more focused and proactive. He’s now laser-focused on Kris and their SOUL, and he’s not looking to make a “deal” anymore. This is a hostile acquisition, though that doesn’t stop him from reminding you that you too can be a “big shot” if you just give him what he wants.

2 The World Revolving

Theme of Mandatory Fun

Have you ever known someone who’s kind of like a social whirlwind? Y’know, someone who, after deciding they want to do something fun, ends up sweeping everyone around them into it, even if they don’t think it’s fun? That’s kind of what fighting Jevil is like in Chapter 1, except that his idea of fun is specifically throwing knives and shooting bullets at people.

Jevil’s theme, “The World Revolving,” is one of the most iconic tracks on the Deltarune OST, as it’s the very first secret boss theme most players encounter. It’s wily and whimsical, like a circus clown, but there’s also an overt hostility to it, like if you don’t go along with the fun times, you’ll get swept up and away like getting caught in a tornado. Interestingly, this was the first song to demonstrate what fans have come to call the “Freedom motif,” a set of melodic motifs that recur in every other secret boss track in the game, named after each secret boss’s hunger for “freedom” in some form.

1 Black Knife

Theme of Pain and Suffering

In the very first chapter of Deltarune, we learn the name of our antagonist from King: the Roaring Knight, a mysterious entity inexplicably able to draw Dark Fountains from the ground and empower Darkners. Naturally, we assumed we wouldn’t see hide nor hair of the Knight until the end of the game, which was why it was so shocking they suddenly showed up at the end of Chapter 3, (nearly) merked Tenna, and challenged us to a fight.

“Black Knife” is the theme of the Knight’s fight, and right off the bat, this one ain’t playing around. It’s fast-paced, haunting, and overwhelming, like an all-powerful predator is bearing down on you from all conceivable angles. The Knight did not come to play make-believe, they are here to knock you out of their way and take what they came for. It’s a track with a very similar energy to 02’s theme in Kirby 64, in that it feels very dramatic and final, though ironically, we hear it less than halfway through the game.