The Neo Mothership is a Pre-Hardmode boss that has a second phase.
Summoning
The Neo Mothership does not spawn on its own and can be summoned with the Neo Locator, alternatively, it can be summoned with the Golden Locator.
Behavior
The Neo Mothership acts like the Angry Nimbus, however, it summons the Neo Parasite upon death
The Neo Parasite acts like Nebula Floater.