Yancy has long, shoulder length brown hair with no bangs in the front. She also has thin antennas that are sticking out of the sides of her head above her ears. Her skin colour is green mixed with a little bit of pink on her face, especially on her cheeks, that could possibly be from her makeup. She wears a pink, long sleeve button shirt with a "U" neck.
Yancy seems to be aggressive and bossy, especially towards Sonny and her parents. For example, Whenever someone calls her "Alien" she seems to take that personally due to her aggression. She also has a sharp attitude and because of this, she rarely interacts with her brother Jimmy. Despite this however, it is shown that she still cares about her brother.
- In Reanimated, it has been established that Yancy doesn't go to school, despite the fact that she is not 18 years old nor does she show any sign of being a prodigy. So with this information, Yancy is more than likely to be home schooled.
- Since Yancy is an alien, she has certain powers that are mentioned a few times during Reanimated. For example, its established that she has AM radio on her antennas. At the end of the movie, it is also established that she has the ability to teleport.
- Despite the fact that she is an alien, She's your basic 16-year-old girl: obsessed with boys, music and always fighting her parents for more independence.
- In Reanimated, she seems to be the only character that points out the flaws with Sonny's habit of shouting out his evil plans.