You call forth a dimensional shambler from beyond space and time. It appears in an unoccupied space within 10 feet.
The dimensional shambler is friendly to you and your companions for the duration. Roll initiative for the shambler, which has its own turns. It obeys any verbal commands that you issue to it (no action required by you). If you don't issue any commands to the shambler, it defends itself from hostile creatures and follows its own instincts.
If your concentration is broken, the shambler doesn't disappear. Instead, you lose control of it, it becomes hostile toward you and your companions, and it might attack. An uncontrolled shambler can't be dismissed by you, and it disappears only when destroyed.
The GM has the dimensional shambler's statistics.
* - (1 point of sanity)