Rebecca Holiday has bright green eyes and dark brown hair, usually tied up in a high bun on the top of her head. As for her attire, Holiday wears a orange turtle neck shirt, with a dark grey vest over it. She has gloves that go a little past her elbows. On her waist is a deep brown utility belt, and she wears dark-colored pants with knee-high boots.
Ben 10-Generator Rex: Heroes United
Dr. Holiday comes amid New York City, where Agent Six found the piece of armor from Alpha, which was later delivered to Caesar Salazar. Later in the base she helps Ben and Rex fight Alpha. While Rex fight with Alpha, Ben as XLR8 keeps her safe. As Ben, White and Rex are in The Bug Jar, she remains in the care of Agent Six, because he was in his coma. Even worse Rex maintains communication with the communicator through his ear. She appears at the end of the episode with other members.