You cannot find Onionsan in Deltarune Chapter 5. But why? I wondered the same thing and started researching the community, and the more I went deep inside the rabbit hole, the more traumatized I got. So where is Onion? The answer is: in your stomach, sort of! YUCK! Keep reading to learn about the Onionsan conspiracy and what really happened at the Hometown lake. But you don’t want to know. Trust me. You have been warned.
What You’ll Read:
What Happened to Onion in Deltarune Chapter 5? (Quick Answer)
If you don’t want to read the whole article, find your quick answers below:
Is Onion in Chapter 5?
No. They are gone and cannot be found in any route, Normal or Weird.
What happened to them?
The community’s leading theory: the Striped Bird (a Gaster-linked entity) silenced Onion after they went to investigate the mysterious song under the lake.
What is the takoyaki clue?
The takoyaki clue: The Striped Bird runs a food stall at the festival, selling octopus dough. Susie says they taste like raw onion. The vendor first asks for Gold (G), Undertale’s currency, not Deltarune’s, then catches themselves and gives the food away for free.
Is this confirmed?
No. This is community theory, not official Toby Fox lore. But the clues are hard to ignore.
Deltarune Onionsan Backstory Explained
If you remember Onion’s story in previous chapters, skip this part. Onion was a giant water monster from Undertale that returned in Deltarune as well. They live in Hometown’s lake and spend most of their time feeling lonely. You first meet them in Chapter 1 if you stand on the lake shore long enough, and they beg you to be their friend.
Things get interesting in Chapter 2. Onionsan tells you a secret. They say they keep hearing a mysterious song coming from deep underwater. Onion promises to investigate the music and tell you to come back the next day. But that tomorrow never comes!
Chapter 3 happens entirely at night. When you check the lake again in Chapter 4, Onionsan is completely gone. Susie just assumes Onion is busy. Although she says she can faintly hear music drifting from the other side of the water. The community widely believes this song is connected to Gaster.
Now we are at Chapter 5, and they still haven’t shown up. Players are often left wondering if they missed a step or if there is a dark conspiracy behind all of this.
What Happened to Onionsan in Deltarune?
When you check the lake in Chapter 4, a weird yellow-and-blue bird blocks your path. The community calls them the Normal NPC (does not look normal at all!) or the Striped Bird. He explicitly tells you not to wait for Onionsan.
This bird is bad news. He has the same sprite design as Goner NPCs or Gaster’s followers from Undertale. He also has a habit of blocking critical narrative locations. You see them guarding the library’s upper floor and the Hometown hospital. He basically exists to stop you from learning too much.
Some players believe that this keeps saying “Wait, don’t” to sadistically mimic Onionsan’s final, desperate pleas. Remember that song we talked about? Onion went looking for that song. The Striped Bird showed up in their place. You do the math.
Did They Cook Onionsan?
In Chapter 5, the Striped Bird runs a street food stall in Hometown that sells fried octopus dough balls. If you try it yourself, you will find a discount code inside: “BALL”. But if you buy some and give them to Susie, she gets completely disgusted. Susie explicitly states the snack tastes like onion! Does this mean the Gaster agent butchered Onionsan and cooked them into festival food?
There is even another red flag to this sick twist. First, the bird asks for “2G”. Deltarune uses dollars, but Undertale uses Gold (G). He then quickly corrects himself and says, “It’s for free”. Could this prove that he is an extradimensional intruder who doesn’t even understand the basic economy of the Light World?!
Do Deltarune Monsters Turn to Dust?
There is a huge hole in the murder theory. In Undertale lore, monsters turn to dust the second they die. They do not leave a physical corpse behind. This means you cannot harvest meat from them. So, how is Onion cooked?
I found a few interesting fan theories for this: The first idea is the ash flour theory. The Gaster agent might have collected Onionsan’s dust and used it as a dry ingredient for the takoyaki dough.
Other players believe Deltarune monsters are built differently. Characters like Susie and Sans actually bleed. So maybe they do not turn to dust immediately. The murderer could have also just chopped off a tentacle instead of hitting a fatal blow.
The final theory will completely blow your mind. It claims that Onionsan is not a magical monster at all! They might just be a regular biological creature native to the underground lake. So they should not turn into the magic dust to begin with.
Deltarune Onion: Normal Route vs. Weird Route
The festival plays out completely differently depending on your choices. In the Normal Route, the Striped Bird stays right at their food stall. He remains in plain sight to observe you.
The Weird Route changes everything. The food stand is empty and stays that way for the entire event. Gaster’s agent abandons their public post. You force Kris and Noelle deep into the lake during this run. The agent likely moves into hidden areas to watch your descent into darkness.
This perfectly explains why Onionsan had to go. They are massive, and their sheer size acts as a natural environmental guard. They would easily stop Kris and Noelle from going too far into the dangerous water. Goner NPCs had to remove that physical safety barrier. Silencing Onionsan directly allows the tragic events of the Weird Route. But then again, this could all be (I hope) simply wrong guesswork.
I know. You are disgusted. So am I! But what a twist. Did you expect this in the Deltarune Chapter 5 Ending? Do you think this theory is false, and we may one day see Onionsan again? Let me know in the comments below.
