Watcher Knight

The Watcher Knights are bosses found in the Watcher's Tower. They appear to be empty armors animated by a swarm of flies.

Attacks
The Watcher Knights can swing their nails twice in attempt to slice the Hollow Knight. They also can curl up into a ball and spin charge to the Hollow Knight, or they can jump while spinning.

Tactics
Since the Watcher Knights attack in groups, it's best to not get cornered by them. It's best to jump above them and hit them from the air, as their spin jump is their only counter to aerial attacks. If you have the Monarch Wings, you can double jump to one of the chandeliers and drop it on one of the Watcher Knights' husks!

Since they have fast attacks, Quick Focus is highly recommended for this fight. Another possible idea is to use Lifeblood items to boost your health, and Stalwart Shell to increase your mercy invincibility time, then damage-race the Knights down. This is a useful strategy if you find it tough to keep track of their attacks.

Trivia

 * Watcher Knight.png way the Watcher Knights spin dash/jump may be a reference to Sonic the Hedgehog, but this may be just a coincidence.
 * Their theme is the same one False Knight uses.
 * Given their name, they are presumably the elite bodyguards of Lurien the Watcher.