A HubGroup is not an element in its own right, but rather a subset of the rig used for organizing rig components. A HubGroup comprises a hub, its limbs, and any tails.
You see HubGroups wherever the CATRig hierarchy appears, such as the CATWindow. The HubGroup name starts with the name of the hub followed by “Group”; for example, RibcageGroup.
The PelvisGroup on the Panther rig
