Biographical information
Species Andalite
Gender Female
Family Unnamed mother
Ajaht-Litsom-Esth (brother)
Occupation Biochemical Engineer
University Student
Affiliation University of Advanced Scientific Theory
Unit 0
Behind the scenes
First appearance The Arrival
Last appearance The Arrival
The Deception (mentioned)
"I am a prodigy. A genius. I do not mean to sound immodest, but it is true."
―Estrid to Aximili-Esgarrouth-Isthill[src]

Estrid-Corill-Darrath is a young female Andalite, an expert biochemical engineer and a one-time romantic interest of Aximili-Esgarrouth-Isthill.


University Student

"At the university, they treated me as a joke when I arrived. A young female! So, of course, they forced me into sub-particle fusion. I was so intellectually frustrated, I wanted to die. Then I met Arbat. He saw past my youth and my gender. He saw what I could do if I had the freedom and the tools. His influence changed everything. I received my own lab. Permission to follow my own area of interest."
―Estrid to Aximili[src]

To be added

Mission to Earth

"I am sorry, Aximili."
"It is not your fault."
"It is. I betrayed you. And your human friends. I have been a fool. A criminal fool. Arbat convinced me that humans were not worth the loss of more galactic life. Unwilling to carry their weight in the fight for freedom. Eager to give up."
―Estrid and Aximili[src]

Estrid is an expert in biochemical engineering specifically in the area of plintconarhythmic physics. She was secretly commissioned by Arbat to fine-tune her prion virus to use against the Yeerks.

Estrid first encountered the Animorphs when Ax and Tobias rescued her from a scene at the mall where she was eating everything in sight. She and Ax briefly flirted, even sharing a kiss to experiment with human mouths. Ax and the Animorphs discovered Estrid's team's true purpose and were able to stop her from releasing the virus. Ax was offered the chance to return to the Andalite homeworld with Estrid and the others, but Ax rejected her offer like he rejected her plan.[1] However, some time later Ax's expresses a desire to reconcile with Estrid.[2]


"We have to stop Arbat and we need firepower."
"Why? To save these filthy Yeerks? Look what they do. Look at what they are! They are going to do that to us, Aximili! They will drag us down that pier, they will force us... NO! Kill them all!"
"Estrid, you said the virus may mutate. You said it might affect humans as well."
"Might. Maybe. But maybe I fixed it. Maybe my last adjustments eliminated the random flux. I do not care! They are not our people. I am not going to let the filthy slugs do that to me!"
"Stay here. Stay low, do not move."
"Do not leave me!"
"Estrid, you are beautiful, you are brilliant. But I really do not think I like you very much."
Aximili and Estrid[src]

To be added


Morph Book Acquired
Kafit bird Prior to The Arrival
Human The Arrival


  • Estrid is an estreen, and is capable of morphing in a few seconds and ending up with a full set of clothing.



  1. The Arrival
  2. The Deception
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