Mimicry.
The raven can mimic simple sounds it has heard, such as a person whispering, a baby crying, or an animal chittering. A creature that hears the sounds can tell they are imitations with a successful DC 10 Wisdom (Insight) check.
Beak: Melee Weapon Attack:
+4 to hit, reach 5 ft., one target. Hit: (1d1) piercing damage
While perched on your shoulder, the raven can't be targeted by any attack or other harmful effect, only you can cast spells on it, it can't take damage, and it is incapacitated.
You can see through the raven's eyes and hear what it hears while it is within 30 meters of you.
In combat, you roll initiative for the raven and control how it acts. If it is slain by a creature, you gain advantage on all attack rolls against the killer for the next 24 hours.
The raven doesn't require sleep. While it is within 30 meter of you, it can awaken you from sleep as a bonus action.
The raven vanishes when it dies, if you die, or if the two of you are separated by more than 8 kilometers. At the end of a short or long rest, you can call the raven back to you—no matter where it is or whether it died—and it reappears within 1,5 meter of you.