History of character has not yet been written.
- This version of the character is exclusive to the continuity of the television series Young Justice and its tie-in comic book series. It is an adaptation of Mattie Harcourt. The original character was created by Peter David and Gary Frank and first appeared in Supergirl (Volume 4) #1.
- Mattie Harcourt was voiced by Cree Summer.
- 1 Appearances of Mattie Harcourt (Earth-16)
- 1 Images featuring Mattie Harcourt (Earth-16)
- Quotations by or about Mattie Harcourt (Earth-16)
- Character Gallery: Mattie Harcourt (Earth-16)
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