Eyes of the King

You summon four fiendish dire bats blazing with ghoul-green light.

(Libris Mortis: The Book of the Dead)  
Originally posted on D&D tools

Conjuration (Summoning)

Level: Hunger 6,
Components: V, S, M,
Casting Time: 1 minute
Range: Unlimited
Effect: Magical sensor
Duration: Concentration + 5 rounds, up to 1 min./level (D)
Saving Throw: None
Spell Resistance: No

Similar information-gathering servitors always accompany Eurynomos, the King of the Ghouls.

The bats, called eyes of the king, send you visual information.

You can summon the eyes of the king at any point you can see, but they can then travel outside your line of sight without hindrance. Even while outside your line of sight, they follow your mental directions on where to explore. The eyes of the king travel together, never separating by more than 40 feet. Eyes of the king travel at 40 feet per round (400 feet per minute) if viewing an area ahead as a human would (primarily looking at the floor) or 10 feet per round (100 feet per minute) if examining the ceiling and walls as well as the floor ahead. They use their own senses to view their surroundings, including Blindsense, which you also benefit from.

The eyes of the king can travel in any direction as long as the spell lasts.

You must concentrate to use eyes of the king. If you do not concentrate, the bats move to attack the closest active creature. Once concentration lapses, the spell ends 5 rounds later.

Material Component: A bit of bat fur.