The Cluster Clan is a group of space pirates, they are Captain Flinthook's main rivals.
"Years of piracy lead to chaos in the cosmos! To better steal from the rich instead of each other, the three biggest corsair crews came up with a strange system to police their piracy. Each solar cycle, Admiral Goldfeathers, Baron Von Guu and Billy Bullseye fight for the rulership of the Cluster Clan! The victor rules the fleets for a full cycle. Some say the pirates leaders are racing to capture Keepers to use their powers to win the rulership!"