|The following information is from the Adventure Time comic book series.|
It may not be part of the same canon or continuity as the animated series.
According to the first page of Issue 1 of Marceline and the Scream Queens, Keila is a "classically trained purveyor of rock" and she "will bite anything but style!" She is very confident in herself and her fellow bandmates. She also always tries to put the band in the best light possible and often has to hold back Marceline from getting too angry. Before their tour begins she says that they're "gonna rock people's brains out." Keila may have a secret crush on Guy, in Issue 3 when she found Princess Bubblegum and Guy together she appeared to be somewhat jealous, and through out the whole series she was always standing next to him.
Keila has light brown skin and big, black, puffy hair. She also has long, pointy ears.
Keila wears several outfits throughout the comic series. One of her most worn outfits is a green dress with green/white socks and green ballet slippers. Another one of her outfits depicts her with a red and gray striped long-sleeved shirt, long black pants, and white boots. During the concert in Issue 2 she wears a short red dress with matching boots. Like Marceline, she wears a hat to protect herself when she is exposed to the sun. Her hat is salmon colored and she has a jacket of the same color. While wearing that hat and jacket she also wears a light brown scarf and pants and a white undershirt and boots.