The Gamers are a faction of Bobs that do a lot of online gaming in Virt, especially live-action Dungeons and Dragons campaigns. Ferb often serves as Dungeon Master (DM) for these campaigns.
Gamers mentioned in Heaven’s River include Randall, Tim, Kevin, Pete and Gandalf, who is the faction’s representative in the search for Bender.
The Gamers volunteer to help in the search for Bender, because it involves a challenge that they find interesting. They devise a plan to allow five mannys to infiltrate the Heaven’s River topopolis. Once the mannys gain entry, the Gamers abandon the project as it is no longer interesting to them.