The file from undertale called mus_birdsong.ogg. This is the song that plays when the bird carries you across to the other side of waterfall. Most of the time the player will use the bird to get to the other side to obtain a healing item called "Nice Cream" and there is a offer by a blue rabbit named the "Nice Cream Man" if the player buys 3 nice creams from him he will give them a free nice cream in return for what is called "Punch Cards" the player will need 3 of them to obtain a free Nice Cream from the Nice cream man. Nice cream heals 15 out of the players health. The Nice Cream man will only be there in a Pasifist or a True Pasifist run as in the Genocide Run the player is informed that everyone is evacuating and so therefore the Nice Cream Man has evacuated too.

UNDERTALE Bird Song

Josh Kernop