| Appeared in:
| Horton Hears a Who!
Dr. Mary Lou Larue, is a whoville scientist of Who University, is the most promising mind in Who-ville. She might seem scatterbrained, but when she has to put her self-peeling potato research aside to help the Mayor save Who-ville, she's up to the task.
She is the first the Mayor goes to after facing proof of their world being a speck floating through space, and later when an overnight heavy snowfall blankets the town (in the summer) she's stunned and nervous about what the "dramatic change in the weather" meant. However she's adamant about helping their town, and immediately marches off saying "It's up to us to save the citizens of Who-ville!" Dr. Larue is later seen when the Mayor introduces her quickly to Horton, and during the "We Are Here" sequence.