Number P, abbreviated for Pendulum Number, is an archetype that is a sub-archetype of the "" archetype.
As the name suggests, members of this archetype are Xyz Pendulum counterparts of the "Number" monsters released in the canon. Sub-archetypes to this archetype are the "Astral" and "Barian" archetypes. They share the common of preventing the controller from Pendulum Summoning unless they have a card of the same sub-archetype in the other Pendulum Zone, and they cannot Pendulum Summon monsters except members of said sub-archetype. Almost all members' Pendulum Scales are 1. "Number P96: Dark Mist Astral-Barian" is especially unique in the senses it is a member of both sub-archetypes, and its Pendulum Scale is 11.
If a "Number P" monster is Pendulum Summoned, it will gain Xyz Material Counters equal to the number of Xyz Materials required for its regular Xyz Summon. If a "Number P" would be destroyed while in the Monster Card Zone, the controller can destroy as many cards in their Pendulum Zones as possible, and then place the destroyed monster in that Pendulum Zone.