Undyne pursues Frisk throughout early Waterfall and early Hotland. Then she tried to stop them from leaving the Ruins by using her HADOUKEN! Toriel tried to feed Frisk snail pie made out of her ex-snail boyfriend. After learning his backstory when he turns back into Asriel Dreamurr, they act kinder to him and brings him with everyone else to the surface. In 'had a Flirting Route' He hates Flowey for trying to kill them and calls him dad for some unknown reason. Genderless Child views Flowey as annoying in some ways in 'was Realistic' but they do seem to get along most of the time until the conclusion of the genocide run. In 'had a Flirting Route', Papyrus was usually very annoying to Child, but Child manages to be considerate of him. Papyrus is constantly trying to be friends with and have sex with Genderless Child. In 'was Realistic', Genderless Child hates Papyrus extremely due to his annoying personality, and his incredible stupidity. Sans does seem to talk to the child in a grouchy tone for unspecified reasons.

However, Child does think Sans is a good person. In 'had a Flirting Route', they sometimes say that they hate Sans, mostly because Sans usually does something to tick Child off, like turning his hands into whoopee cushions. Overall Genderless Child says Sans is 'alright'. In 'was Realistic', they both love to drink together and have a very similar characteristics. Frisk and Sans have a mostly positive relationship in both series.

Undertale sex animations