Krone

Sister Krone or Krone is a sister/helper in The Promised Neverland and helps run the Grace Field House orphanage with Madam Isabella.

Personality
Like "Mama", Sister Krone is a evil two-faced caretaker of the children.

Trivia

 * Her name "Krone" is the german word for "crown", which fits with her desire to take Isabella's postion as the top of the Mamas.