The Cockroach was an enemy of Howard the Duck.
The Cockroach was originally a normal insect within a bookstore in New York City. The owner of the bookstore, R. L. Haney, purchased a large order of books from a dealer in Cleveland, which contained the Cosmic Key (which had been hocked by Howard the Duck in order to buy clothing). Unaware of its true nature, Haney placed the Key inside a desk drawer, where it was encountered by the cockroach. Mistaking the Key for food, the hungry cockroach nibbled off the tarnish on the Key, and was filled with magical energy. It staggered back to the paperback section and transformed into a large, humanoid Cockroach.
Hemlock Shoals, an insectoid native of the extra-dimensional realm Maltesia, came to the Barqu Bookstore on the trail of the Key, which had vanished from his dimension during an encoutner with the sorceror Pro-Rata months before. However, when Shoals located the Key, the Cockroach leaped out of the paperback section and claimed the Key for himself. The Cockroach realized that he could use the Key to similarly evolve an army of Cockroaches and take over the world.
Shoals, Haney, and Howard the Duck (would had traveled to the bookstore alongside Shoals) pursued the Cockroach, hoping to stop him before he could succeed in his plans. The Cockroach evaded all attempts to capture him, until confronted by Howard, who had anticipated the ramshackle hotel that the Cockroach had chosen to search for his fellow insects, and cut him off. The Cockroach attempted to mesmerize Howard with plans of joining him in power, but Howard trapped him in a pre-made glue-trap and took the Key from him. The Cockroach tore free from the glue and came after Howard again, who doused him in a powerful insecticide. In desperation, the rapidly weakening Cockroach leapt at Howard one last time, but he was skewered by the bladed walking stick of Hemlock Shoals, thrown by R. L. Haney. In apparent death, the Cockroach returned to its original form. The Cosmic Key was returned to its rightful home in Maltesia.