A Living Demiplane

As we entered the Lich's Tomb chamber, Glimbo noticed a shadowy rectangle creeping along the stone floor towards me. He was too late to save me from being pulled into the other dimensional chamber, but he had the courage to grab hold of my leg, and hanging on tightly followed me through. Lucky for us both that he is a student of magic.
-Harlwick the Halfling Rogue talking about the courage of his Wizard friend Glimbo'Two Tomes' Thistleberry

A Living Demiplane

A Living Demiplane is a Demiplane Spell that has become vaguely self-aware. It is a shadowy rectangle, 5 feet wide and 10 feet high, which creeps along flat, solid surfaces and groans softly when it moves.
When a Living Demiplane encounters a creature small enough to fit through its doorway, it tries to pull that creature into itself, then deposits the victim in an extradimensional chamber.

Basic Information

Anatomy

Construct (Living Spell), A Living Demiplane: A Living Demiplane is a shadowy rectangle, 5 feet wide and 10 feet high.

Ecology and Habitats

Areas of wild magic and sites that have been ravaged by powerful eldritch forces.

Dietary Needs and Habits

Living Spells don't require air, food, drink, or sleep, but remain in an area that consists of ambient magical energy.

Additional Information

Perception and Sensory Capabilities

• Darkvision 60ft, and 
• Passive Perception 10

Genetic Ancestor(s)

• Living Spells

Origin/Ancestry

Construct (Living Spell)