David Alexander's gang was a group of people led by David Alexander, who was hired by The Harrybo Company to help hunt down Michael Rosen during his expedition to the Island of the Plums. The group initially came to existence after four people found each other in 1989, whose parents were all killed by the parents of Michael Rosen during October of 1972 during the shooting (and bombing) of Manchester Airport. They swore to avenge their fallen parents by hunting down the members of the Rosen Family, and showing them what their pain feels like.
In January 2009, David tricked Michael Rosen into believing that he and his gang would join him on the expedition to the island, but they only said this after receiving word from The Harrybo Company, by which they were hired, that Rosen would be setting sail to the island the Harrybo Company had been looking for. They had to find out where exactly he was going and be able to spot the ship judging by how it looked like from afar. Michael managed to find a new, proper crew, but meanwhile, David and his gang went off to Jamaica (which Michael mockingly described as going to a "brothel" in Jamaica) to visit the robot factory, which was placed there by The Harrybo Company. Richard (who was secretly Toenail Pizza, who had already begun the battle) called for back-up. David managed to track down Rosen and, with the help of his gang and hundreds of robot pirates, they set sail to the island, using one of The Harrybo Company's mechanic pirate ships. Underway, they recognized Rosen's ship, and began to attack it using robotic plums.
In the end, Michael and his crew won the battle and captured David and his little gang, who only managed to kill Lydia out of all of Michael's crew members. Later, they were found dead by Toenail Pizza, who decided to take a look at Michael's crashed ship after losing him (and the Battle of the Island of the Plums) once again. It is as of now unknown what happened to them after that.