Ariella Third
Ariella Third is one of Professor Third's daughters and Ingrid's elder sister.

Once while their father was down with a cold Ariella and Ingrid stayed home to nurse him back to health, Ariella spending time in the kitchen fixing soup[1]. After tasting it, she remarked "Needs more aloe".

Ingrid had mentioned her a few times. Once in answer to Fillmore's question if she had any siblings[2]. Another was when the rapper "Checkmatey" asked if she had a sister and if she looks like her[3]. Ingrid replied, "Taller".


  • She is voiced by Tara Strong.


  1. A Cold Day at X
  2. Nappers Never Sleep
  3. Of Slain Kings on Checkered Fields