Annie is a young girl who narrates the movies that sometimes make cameos in some propaganda posters. She wears red framed glasses and also works with Moby. She has a sister named Mia who talks on the cell phone too much, is afraid of mice and allergic to dust and gets angry when Annie says something embarrassing about her. There are many hints in BrainPOP Jr. that Annie is Hispanic, like her dog's name (Sr. Marice), and she sometimes refers to her father as "Papi". Her best friend is named Becca. She is allergic to eggs and gets red in the face when angry or embarrassed. She is always very cheerful, curious, and optimistic.
In BrainPOP Jr., Moby shows his emotions more, like he is able to cry and much Moby can't do, such as sneeze, eat human food, sweat and drink water. He can also can be sick and smell flowers, which are notable inhuman traits.