The Hollow Knight:

The Hollow Knight serves under the direct supervision of The Vampire Yanos Aldren and has served under him for since before the annexation of Khu’Vahl by the Kingdom of the Night. He leads his armys into battle and provides protection for his master in times of need.

This particular undead is specifically a stanch and hearty foe that is said to have been bested on the battle field numerous times but always gets back up to serve his purpose and his masters call. Usually perusing whatever his masters desires until they are fulfilled.