Rojo (voiced by Jennifer Hale in the original Ben 10 and Omniverse and Kari Wahlgren in Ben 10: Ultimate Alien) is one of the three secondary villains in animated television horror film Scooby-Doo: Unknown Assailant and also a minor villain in Ben 10 series. Just like in the original series, Omniverse, and Ultimate Alien, she is still a member of a biker gang. Her name means "red" in Spanish. In the German dub, she is known as Rot while in the French dub, she is known as Rouge.
Rojo, along with two bikers Ms. Grunion (Allison Janney) and William Harangue (John DiMaggio), travels to Ponyville and stops in a convenience store. In the store, Rojo takes to hassling customer Thunder Lane (Trevor Devall) and Rainbow Dash (Ashleigh Ball). Having grabbe Thunder Lane's black wallet when he attempted to throw it to Rainbow Dash, Rojo taunts Rainbow Dash, making Rainbow Dash grudgingly ask for it back and address her as "Red".
After Thunder Lane mangles their motorcycles as revenge for troubling him and Rainbow Dash Rojo and her fellow bikers follow Thunder Lane and Rainbow Dash back to the Sweet Apple Acres. Despite being reluctant in participate in her friends' plan to burn down the Sweet Apple Acres barn, Rojo, however, after being reassured by Ms. Grunion that nobody will get injured, wanders off to look around. Going into the barn, Rojo nonchalantly begins toying with some of the equipment lying around on the second floor, eventually climbing up onto the second floor. Finding and rope and rake used to hoist hay, Rojo begins swinging from it for fun. Her compatriot William Harangue sees this and demands Rojo to come down this instant, so they can help Ms. Grunion in her revenge plans. Unseen by William Harangue, Rojo was ultimately grabbed by Fauntleroy Donaldson and pulled back into the barn, where Fauntleroy impales her to a barn rafter by the throat with a sharp pitchfork. Shortly, before Fauntleroy kills him too, William Harangue finds Rojo's corpse, which Fauntleroy later moves. Rojo's corpse, along with the corpses of Ms. Grunion and William Harangue, were found by the authorities and taken away by the paramedics. In the deleted scene, Velma Dinkley found her bloody corpse tied to a mahogany chair in Twilight Sparkle's library.