About

Papyrus and Sans' Brothers or Secret Skeleton Brothers, including Baby Bones, is a series of Undertale memes that purposefully misinterpret selections of Sans and Papyrus' dialogue, often sections that begin with the phrase "my brother," as references to the characters' unseen brothers, including examples like "my brother will" and "you dirty brother killer." The memes began in March 2023 on the /r/Undertale subreddit, when Redditor u/Midnight2am posted a screenshot from the game in which Sans says, "That's for baby bones," the user mistaking the dialogue as a reference to a brother named Baby Bones. The meme snowballed over the following years, inspiring memes about Baby Bones and other non-existent skeleton brothers, for example, Prunsel.

Origin

On March 13th, 2023, Redditor u/Midnight2am posted a screenshot from Undertale to the /r/Undertale^[1] subreddit titled, "Found this while going through Snowdin, is this a lost skeleton brother or something?" The screenshot shows Sans saying, "That's for baby bones." The post gained over 1,500 upvotes in two years.

In the screenshot, Sans is actually calling the "Junior Jumble," a word jumble game within Undertale, easy by calling it "baby bones." It is unclear if u/Midnight2am genuinely misinterpreted the dialogue or purposefully misinterpreted it to troll subreddit users.

Spread

Baby Bones became a running meme on the /r/Undertale subreddit and in other Undertale communities over the following years, also inspiring other memes that misinterpret the game's dialogue as references to skeleton brothers.

On March 14th, 2023, Redditor u/Seen-2021 made a parody of the post by Redditor u/Midnight2am to the /r/Undertale^[2] subreddit titled "What if Sans is talking about a different brother?" sharing a screenshot of Sans saying "you dirty brother killer," garnering over 1,300 upvotes in two years.

On March 22nd, 2023, Redditor u/arro57 made a post to the /r/Undertale^[3] subreddit showing an animation featuring a mockup of Baby Bones set to an original song, writing, 'I know we're all sick of Baby Bones, but why did nobody ever talk about his Boss Theme?" garnering over 2,300 upvotes in two years.

On March 19th, 2024, u/ExtremelyBored99 posted some altered screenshots from Undertale to the /r/Undertale^[4] subreddit about Baby Bones, writing, "Why does nobody talk about the third skeleton brother? He's mentioned twice and yet nobody seems to care," garnering over 2,800 upvotes in a year.

On April 24th, 2025, Redditor u/anodocoelho posted a piece of fan art to the /r/Undertale^[5] subreddit depicting Sans, Papyrus, Baby Bones, Dirty Brother and other examples of "brothers," garnering over 2,400 upvotes in four months.

On May 2nd, Redditor u/Aromatic-Dirt-6725 posted a meme to the /r/Undertale^[6] subreddit sharing a screenshot of Sans saying, "seems like you're gonna fight my brother pretty soon," titled, "Sans has a 6th brother named pretty soon?" garnering over 1,400 upvotes in three months.

On August 12th, 2025, X^[7] user @deltaruneleaks posted the "pretty soon" screenshot, writing, "'Pretty Soon' will not be appearing in future deltarune chapters," garnering over 15,000 likes in two weeks.

Later that day, X^[8] user @peeeeeeeeeeaf posted another version of the meme about a brother named "Pretty" as a quote-repost, garnering over 19,000 likes in the same span of time.

On August 25th, X^[9] user @NikisLair posted a piece of fan art depicting Papyrus' brother "Today," garnering over 11,000 likes in three days.

Various Examples

Search Interest

External References