The Operation: Aliens trading card set that was published by Dark Horse Comics as part of the Aliens/Predator Universe trading card set from Topps in 1994.
The entire set consists of 15 trading cards, each with original artwork by Den Beauvais on the front side and text by Jerry Prosser on the rear. Together they form a short story set within the Alien expanded universe. Certain elements depicted in the trading cards are derived from both Kenner's Aliens toyline, as well as Dark Horse Comics' Aliens comics, although the story seems to be largely original.
The plot starts with a group of scientists studying the Xenomorphs at Grant Corporation Station 13 sending out a distress call when their specimens escaped and begin rampaging through the base. The signal is passed on to Lieutenant Roberta Benitez of the United States Colonial Marine Corps, who is ordered to mount a rescue and "sterilization" mission. Benitez and her Marines land on the moon base and begin the search for survivors. They are soon attacked by Xenomorphs and forced deeper into the complex, taking casualties along the way. Several of the Aliens they encounter are strange new forms resembling Bulls, Gorillas and Snakes, created by the scientists through gene splicing.
Benitez and her remaining men find a surviving scientist and make their escape, passing through the Hive and killing the Xenomorph Queen along the way. They make it to the dropship and take off, but are attacked by a Flying Queen. The pilot successfully kills the creature with missiles, before returning to their starship in orbit and destroying Station 13 with a nuclear strike. Benitez sends off her mission report, lamenting the loss of two good men, solemnly concluding, "When will we learn?"