Viewing Mod
The Binding of Undertale
TBOI x Undertale Crossover Mod
Created 2 years ago

Get the AB+ version here:

Thank you very, very much for the Mod's overwhelming reception and 50000+ Downloads!

This mod replaces characters, music, bosses and floors with Undertale content! Enjoy!

by tipo19 and Opscat

Talk to us!

Q: Do I need Afterbirth for this to work?
A: No. Inside the folder, you can see there is a "Rebirth only" folder.

Q: Where's Toriel, Asgore and Chara?
A: You installed the Special version. Re-install the mod, but only Install the Basic version, not the Special one, and you'll get those characters.

Q: My game Crashes!
A: Install the mod, then delete Costumes2.xml. Be aware that this might cause characters to change appearence
when collecting some items.

Q: I'm in Snowy/Waterfall and the screen is pitch black!
How to fix:
Go inside resources/gfx/Background and delete the "Black" images. Those being: 8bitclouds_64,8bitclouds_64_black,8bitclouds_642,8bitclouds_643,blue_overlay and orange_overlay.

Q: I see a credits page, but not the Challenge page! Where is it?
A: If you want to see the challenges, just go inside gfx/ui/main menu and delete challengeph.png

Q: Is this compatible with Mac/Linux?
A: As far as we know, it's compatible with mac. It's super buggy with Linux and we plan on fixing of it later.

Q: I found a bug! Where can I report it?
A: Either Private Message me through Steam or the mod's blog.

Q: Can I suggest/submit stuff?
A: Yes! Either go to the mod's blog or post a comment in this comment section.

- The mod can be very glitchy on Linux and Mac.

- The Rebirth-only version is very early so expect glitches.
(Example: No Gaster Blaster. For some reason, rebirth ignores the familiar folder.)

_ In Snowy Rivershore and Waterfall, the screen might go black, but you can still hear the sound. Read the FAQ, you can find the answer there.

-Bugfix for Mac:

-More item reskins. (Taking Suggestions!)
-Waiting for Afterbirth+ !!!!

SwingPoynt v2:
iVertrox (Spanish):



Special Thanks to:
Patkall - Sprites
FAz - Sprites
SoaringSparrows - Original Concept
IKARUS - Song Credit
/u/Haylex - Tem Shop Mod
Draexzhan - Miscellaneous Item Sprites
reijigazpacho - Logo
Felix ( - Nightmare Sprites and the Omega Flowey boss
Sophomore - Miscellaneous Item Sprites
/u/otherhand42 - Miscellaneous Help
engineerthecowboy - Rebirth Testing
Toby Fox - Undertale


x 7888

- 20+ New items and 3 transformations, by the talented FAz!

- Community Update: 20+ items and a Flowey transformation, by the amazing /u/Patkall! Thank you!

- Fixed compatibility with the newest Isaac patch.

- More items

- New version whenever Afterbirth+ Hits

- Fixed Rebirth Compatibility

- Rebirth Support! (Thanks to engineerthecowboy for testing!)

- Community Made items!

- More items, like Muffet's Pet and Lil' Whimsalot!

- New character: Mad Dummy!

- Made it easier to understand how to install/know what version you're using.

- Small item replacements.

- Balanced some stuff.

- Fixed Special Version having a hybrid of Gaster and Temmie.

- Two New Characters, Gaster and Temmie.

- Two new end bosses, Omega Flowey and God of Hyperdeath Asriel

- HP up item reskins

- Some music added

- Napstablook now Starts with Dapper Blook

- Frisk starts with Purity (Soul Colors)


- Only a small amount of items now change your character.

- Asgore, Sans, Mettaton, Toriel, Asriel and Undyne have new costumes wich will help prevent their appearence to change.

- Fixed some naming stuff

- Made the Character menu less messy

- Toriel starts with proper items

- Blue womb is not dunked up anymore

- Characters don't have their items because you didn't unlock them was fixed

- Napstablook glitches when picks up a item was fixed

- Frisk doesn't have Isaac's heart, just <3

- Papyrus lost 1 heart container inside his spaghetti

- Mettaton has better bombs and Tech.5 (not tech 2)

This is pretty popular, but I'm not a fan.
I Just Played It Not Recording, Planning It!
Hi hello hello there, uh, was just thinkin', sans replaces cain, right? But wouldn't it be better if he replaced "The Lost"? 'cus Lost gets one-shoted (exactly like sans), and the holy mantle that u can unlock for him would be the "miss", no? Maybe it's a lill' too much to ask.. :b

Anyway, great mod
It's giving me the mod in a .rar file, that i have no clue how unpackage.
I Installed It But.Like When I Play Undyne Spears Dont Come Out Is That Just Me Or :PPPP

i can help even though i am not the creator:
Buy Afterbirth (but if you buied afterbirth and you are looking forward to buy AB+ install the AB+ version here:
how do i install it that it works????
je pense qui faut le DLC AB et si ta AB+ utilise se lien
Where's the rebirth version?, do i only need to click download here, or there's a special link?
there are 2 things in rar. file afterbirth ver. and rebirth one no need to thank
Is there a way to install AB+ version without using steam?
nope, (if ur a pirate boi ur gr8 m80)
Why are people saying it dosent work it works the people are just not installing it right
November 2, 2017 - 5 months ago

We now have a store with modding-related and Antibirth shirts, with designs by the amazing Elko! The price may be going up a little soon, so if you wanted to get them at the lowest price they will be, now is the time. Special thanks to DragonoidSlayer for helping get this set up!

Store Page