J. Curby Gremlin is a character in Cars 2.
"J. Curby is the current patriach of the Gremlin crime family, but he got there by some unconventional roads. Don't let the rough exterior fool you - he was once maître d' of the flagship restaurant of superstar Motorio Brake-tali. He even soaked in the best of the big city's shows. These days, J. Curby has turned to a life of mischief, serving up danger and singing a more ominous tune...."
J. Curby Gremlin is a purple and yellow striped gremlin car who works with Professor Z. He is head of the Gremlin family. J. Curby and the other main heads of the three lemon families (Pacer, Trunkov, Hugo) attend a meeting with Professor Z in Porto Corsa to discuss their evil plans about discrediting Allinol by using the electromagnetic pulse generator disguised as a camera to cause the racers in the World Grand Prix that use the gas to blow their engines and crash, and ensure that all cars keep using conventional fuel to secure the profits of their "lemon" organization who managed to secure the largest unexplored oil resources in the world. J. Curby is seen smiling at the idea. He mentioned himself that he is from Detroit, Michigan when Victor Hugo entered the meeting room in Italy.
Near the end of the film, J. Curby is sprayed by Red from behind, being thrown in the air, and getting stuck in a narrow gap between a building and a fence. He is arrested in London with his fellow lemons.