Little Ghost is the final boss of Chapters/Basement. Her boss theme is Pulso Profundum in the download version, the normal boss theme in Binding Of Isaac Rescratched and Chorus Mortus in the Steam version.
A teenage girl's corpse is thrown out of a chest. Then, white liquid sprays in every direction, summoning the girl's soul.
Little Ghost's legs run into the wall causing it to go to its original liquid form.
Whats left of Little Ghost stares at the screen for 2 seconds. Then, Little Ghost explodes awakening Night. If your playing as Night, you get the portal to Necropolis 3.
In Rescratched, she isn't the final boss but she replaces Duke Of Flies as the 2nd boss.
On the title, Little