Editing Spelljammer Helm (section)

=Orbus=
An Orbus is a [[beholder]] mutant specially bred to act as a living helm. We know very little about their looks, beyond them having the appearance of a "stunted, albino" beholder. Like the Series Helms, orbii (as they are called in a collective) can pool their magical abilities to generate thrust, though for some reason the circuit can only handle 5 orbii at a time.

An Orbii pool grants 1 Ship Rating per orbus, and can move up to 60 tons (20 per orbus, capping at 60). It's unknown if orbii could work for other races, because the beholders would rather kill them than let them be used by other races.

You could way they are the Beholder equivalent of Navigators from Warhammer 40,000.