In Chapter 4, when you ask Swatch for recommendations, he recommends Ralsei the Mochi Paw Pastries, Kris the Tiramisu Cat Ears, and Susie the Black Tail Churros. However, when you put the Black Tail Churros thing related to FRIEND and the Prophecy, you might get interested, because Susie had to possibly do something to FRIEND for something like this to happen. So, what happened to FRIEND?

According to the Prophecy, 3rd Sanctuary, They'll see the tail of hell take crawl. And, many FRIEND designs that are fanmade has a black tail that looks like the one that was cut from the Chapter 3's 1st Board restored by Deltareimplented. So, this could include some type of theory somewhere, that something bad DEFINITELY had to happen to FRIEND for this to happen.

A comic from 9375608084 on Reddit reposted by Loud_Fenian_4227 on r/Deltarune claims that Asriel owned a cat that was familiar to FRIEND named Cueball, where Kris opened the window, but the cage was open, causing Cueball to "fly out of the house", according to Toriel. However, when did Kris think they lost Cueball? Was it when they opened the window? Or when they opened their cage? Because let me tell you. It was neither.

An unthought. An unfeeling. This truth lies in-between. Behind limits.

It also theorizes that Kris had a bird but it died when they wanted it to fly far, far away...

The comic also says "Cueball is dead.", indicating that Susie may have found Cueball, but instead of bringing it back to Kris, Toriel, Asriel or Asgore, Susie ate the cat's tail, and it may have killed the cat, because she ate the tail.

However, this is just a theory. A game theory. But, remember this from FRIEND themselves.