A creature hosting an astral snapper’s astral form must make a DC 13 Wisdom saving throw each time it finishes a long rest. On a success, the astral snapper is ejected from the host and the Astral Plane into an unoccupied space in the Material Plane within 10 feet of the host and is stunned for 1 round. On a failure, the astral snapper consumes part of the host’s internal organs, reducing the host’s Constitution score by 1d4. The host dies if this reduces its Constitution to 0. The reduction lasts until the host finishes a long rest after the astral snapper has been expelled. If the host’s Constitution score is reduced to 0, the astral snapper exits the host’s body in the Material Plane by tearing its way out through the abdomen. The astral snapper becomes completely corporeal as it exits the host, stepping out of the host at its full size.

From the time the astral snapper succeeds on the initial dive into the host through the Astral Plane until the moment it emerges from the host’s abdomen, it can be seen by any creature that can see into the Astral Plane-its head buried in the host’s back. The astral snapper has disadvantage on Wisdom (Perception) checks and is effectively stunned when in this position until it takes damage.