Watchdog

Your faithful friend stands watch at the entrance when you don't want enemies to take you by surprise. The target remains at the location, keeping watch for creatures. You must remain within 1 mile of your companion, or the spell ends. When any creature approaches within 30 feet of your companion, you're immediately alerted with the effects of the alarm spell. When this happens, you see the image of whatever creature triggered the alert as your companion would see it. You can Dismiss the spell. When this spell ends, your companion immediately teleports to an unoccupied space closest to you.