The 9th Human Ending

The 9th human ending is accessed after completing the Glitch Kat battle

Since Glitch Kat changed the timeline after the battle Asriel and Chara will be revived and standing next to Frisk. Glitch Kat will speak with them before exiting the UNDERGROUND. They will stand on the edge of the cliff like in the original game ending and the end credits will roll. After the credits end you will recieve a new file to access it type %appdata% in your windows 10 cortana and go into local/the9thhuman to access the file, you will have a wallpaper with "the 9th human ending" sprawled above the group