With Deltarune Chapter 5 coming out in a few days, this account will be taking a break posting trivia to let people play through the Chapter and enjoy it without spoilers, including the admins of this account. Trivia will return on July 8th, see you then.

In the S rank changing room, when you approach one of the stars on the wall it will fall onto the ground and make a spat sound effect.

Toby also suggested the name Cronus for the character Eridan Ampora, which later got reused for Eridans Dancestor.

Jens Bergensten, CCO at Mojang, has stated that Toby is a great composer in reply to someone saying that they should get Toby as a guest composer for Minecraft.

In the demo for the Garten of Banban spinoff game "Banban Isle Rangers", there is an Undertale reference.

Recently an anonymous backer from the Kickstarter of Undertale compiled every update from the Kickstarter, including all the backers-only ones. (Archive in replies)

In a new video by the Youtuber CiblesGD, she counted every tree in Undertale. With this newfound knowledge we can now say there are 9,252 trees in the entirety of Undertale.

During Chapter 4 when you have to make a drink for Alphys, every drink combination has a different name. Alphy's special combination is not mentioned by name in game, but in the files it is called "Dragon's Scar".

There is a typo where Susie says another him in the third textbox of this scene.

Toby Fox will be a composer for Hiveswap Act 3, despite previously stating he wouldn't be as he did not have time.

On James Roach’s resume website, it says that he has been a sound and music consultant for Deltarune from 2018 to the present, even though his name does not appear in the credits.

The swamp area in Deltarune Chapter 5 reuses the same tileset from Chapter 1 for the grass and bricks.

During the development of Deltarune, if there was ever confusion on how a certain pose or animation would be portrayed or done, Toby would act out the animation to demonstrate exactly how he pictured it.

In the Second Sanctuary, leaving Gerson's study after entering it will spawn a battle with Wicabel and Organikk. However this battle doesn't have its own battle message defined, so instead uses the default one meant for test enemies which is "It is known."

There is an unused Key Item in Chapter 3 called the Backstage Pass. As seen by an old preview of the Green Room and by Toby's own admission, originally there was no S-Rank room, which likely means this item would have been used to go backstage and play Mantle.

During the climbing scene in Chapter 4, one frame of Jackenstein's climbing animation has a missing pixel.

In the code for setting up which character uses which talk sound in the boards of Chapter 3, Tenna's talk sound is set to snd_txtspam2, the talk sound for Spamton NEO. But it's never heard in game as Tenna has special code for playing his talk sounds that overrides this variable.

Happy Birthday to Chapters 3 and 4! Recently a glitch was discovered to skip the entirety of Board 2 in Chapter 3, and doing this even gets you the Z-Rank which lets you continue the Sword Route as well.

Chapter 3 of Deltarune (Left) has 30 invincibility frames as opposed to the normal 40 in any other Chapter, meaning between hits there is 10 less frames (about 0.3 seconds) of leniency before you can be hit again.

Alternia, the name for the Homestuck troll homeworld, was suggested by Toby "Radiation" Fox, who also suggested naming it "Dorn".

The "Up Next" sign in the Muffet fight is inspired by The Arena from Kirby Super Star.

Deltarune won 1st place in the RPG category during the 2026 Dengeki Indie Awards, and Toby even wrote a small message for it. (Translation in replies)

For a time in Cookie Clicker, people could donate to add a custom grandma name to the game, one of these names which was added as an option is "W.D. Grandma", a reference to Gaster.

In 2018, Toby Fox collaborated with Itoki Hana on the song "74", where he composed the song and provided guest vocals.

Toby Fox was inspired to start making Undertale by reading about programming arrays on Wikipedia.

Jackenstein's red pumpkin bullet has some very long and funny sprite names.

The song used in the video "Nyan Cat 2: Rainbow Boogaloo" is a song from Homestuck made by Toby.

The fanfiction website AO3 has 3 "Work Skins" you can apply to your fanfics. One of them was made specifically for Undertale fanfics, and it allows you to use the fonts from the game in your works.

The Deltarune song "Fanfare" is a very small snippet of a longer song from the 2016 game "Rose Of Winter", which Toby Fox made the soundtrack for.

Ramb is coded to have different facial expressions in his final dialogue with Kris, though they are ultimately unused as he uses a singular petrified sprite in-game. By modifying the game they can be re-enabled.

In the create script for Shadowguy's enemy object there is a boolean named "dingus", which defaults to false. Setting it to true doesn't affect anything, as this is the only time this variable is called and is nowhere else in the game's code.

The option to fall back asleep at the start of a Chapter if you have completion data is unavailable if you start Chapter 4 with a save file that completed the Chapter 2 weird route, as it would skip important events.

As of Chapter 3, the Pink Ribbon and Twin Ribbon were nerfed. The Pink Ribbon now reduces TP gained from grazing and graze time by 20%, and the Twin Ribbon does the same by 25%. These effects stack on top of each other.

The track Undertale was inspired by the song REDLINE DAY from the movie REDLINE. Toby notes that the song's lyrics unintentionally align with the narrative themes of Undertale. He also cites the song Pneuma from the live-action Solanin film as inspiration for the song.

The intro for the bonus Susiezilla minigame is slightly different depending on when you first activate it. Most notably, Susie is bored and not enthusiastic if first activating the minigame after confronting Tenna after round 2.

The White Cloak and Black Monster in the Sword Route both have placeholder sprites, being a brown deer and a black deer respectively. In the game's files there is a variable named "toriel", which is always true. If set to false it replaces Black Monster's sprite with the deer.

Toby Fox is listed in the special thanks of the pilot for the new Glitch Productions show "Gameoverse".

A new album of Deltarune remixes has appeared on Toby Fox's Soundcloud, Spotify, and on Youtube. The album is centered around guitar remixes done by Geoffrey Day and probably will be officially announced soon.

If you didn't talk to Onionsan in Chapters 1 or 2, when standing at the lake in Chapter 4, you will get a unique cutscene with Susie.

When you use the OldMan act on Balthizard for the first time, the Old man comes in and asks how the fight is going and also asks "Ya winning, kids?", a line that references the "Are Ya Winning, Son?" meme.

The dialogues in Undertale and Deltarune about bad and dangerous combinations is likely a reference to some obscure dialogue in Earthbound where a cow says "Cows and carrots?... That's a nutty combination!"

The Lode Stone item in Deltarune has several unused flavor texts as well as unused equip dialogue.

When you investigate Noelle's computer, Susie can comment on a "green dog puppet" wallpaper. This is likely a reference to a SiIvaGunner upload of Field of Hopes and Dreams, where Noelle wears a hoodie themed after GIR from Invader Zim, which became popular in the fandom.

When using the "Rival" act against Bloxer, there is a bug where Susie's talk sprite stays on screen when the narration says the enemies became tired.

In the original Survey_Program release of Deltarune, Jevil didn't give you a shadow crystal upon beating him because they didn't exist yet, shadow crystals only got added with Chapter 2 in the Chapters 1+2 Demo.

There is a visual bug when Tenna transforms all your commands into the ACT option during the Doom Board, for a few frames before everything changes into ACT, Kris loses the defend option but gains the magic button in the menu.

In Homestuck: Beyond Canon, a list of possible Kind Abstrata (weapon types) is shown. One of these listed is "anyngdogkind", a reference to the Annoying Dog.

Unlike the egg rooms in Chapters 1 and 2, which have a 1/50 chance to send you to them on the screen transition for their respective room. You will always get the Chapter 4 egg room after 8 attempts.

During The Roaring Knight's Box Cutter attack, getting hit by the slash itself will always leave you at 1HP. And if the target is already at 1HP, it shows up as a "MISS."