An "imaginary" can refer to any permanent umbracosm resident, many of which would have less ability or tangibility in the corporeal plane as they are. They can range between fantastical lifeforms, spirits using inanimate objects as bodies or body parts, representations of objects or abstract concepts.

Animate objects: statues, toys or other objects that have developed sentience in the umbracosm. Those whose personalities were not conceived by the Umbracosm responding to belief or sentimentality from dreamers may have been disembodied souls before finding a vessel they bonded with. In some cases, the vessel may act more as a body part, such as the head or heart, than the tenant spirit's entire body.

Dark masses: amorphous dark masses, some of which may be a degenerated silhouette and some of which may have been manifestations of significant emotional turmoil from the beginning. They are often drawn to negative emotion and reputedly cross over to prey on vulnerable sleepers through sleep paralysis and night terrors.

Silhouettes: shadowed astral bodies, some with simple white masks embodying however much they retained of their former identities, personalities and memories after losing anchorage to their corporeal lives. They may reform as they rebuild their senses of identity from scratch, if they do not deteriorate or find vessels to claim as their new bodies.

???: umbracosmic examples of abyssal gigantism, eldritch leviathans of the Void that devour collapsed limbos like whale falls. Since their emergence in the late 1930s, they have had steadily more definition and influence in the umbracosm.