I'M NOT RALSEI! BUT I'M ASRIEL! is a meme in the community for the 2018 indie game Deltarune, popularized by the YouTuber known as Bitti. It is used in videos to give Ralsei an exaggerated expression, typically in unserious videos.

Origin

In June 9th, 2020, A YouTuber called Karim Hani uploaded a sequel to his fan animation of Deltarune. In this video, Kris arrives in Castle Town, to kill the other two protagonists, Susie and Ralsei.^[1] When they do so, Ralsei reveals himself as Kris' brother, Asriel, before Kris snaps out of it.^[2] The video, however, has since been taken down. This was initially forgotten until in April 10, 2025, a Roblox youtuber called Starism repurposed his extras channel, Starism Plus, to be an Undertale/Deltarune dubbing channel, known as Bitti, with the first video being a dub of the original animation.

Spread?

In Bitti's other videos, sometimes when Ralsei is in despair, or getting desperate, the face used when Ralsei reveals himself as Asriel is placed over the face in the video. This was used as a running joke throughout Bitti's videos for a while.
It has also been adopted by Twitter/X user Teox, who makes various gifs/short videos portraying satire stories with the mindset of the Undertale and Deltarune fandoms, aptly titled "Deltarot."

Okay, but where is it now?

The face is still used in Bitti's videos, with the phrase I'M NOT[___] BUT I'M appearing in a later video, and while Deltarune memes may be very fast passing, this is still one of the more memorable jokes in the community.

^[1] This was before Chapter 2, when in the previous chapter, Kris pulled out a knife and looked at the player, menacingly, but it was then revealed that they ate Toriel's pie with the knife.

^[2] Ralsei bears a striking resemblance to Asriel, and his name is an anagram of Asriel, aswell.