Cut Content (Hollow Knight)

Blundering Oberlisk
A centipede-like charging creature removed from the game fairly late in development. It's Journal entry would've read ''This placid herbivore doesn't seem to wish harm on any of the creatures it shares a habitat with. However, its careless nature and bulky weight sometimes leads to messy accidents. "That millipede thing? Yeah, it never really had it's own area." -Ari Alexander''

White Knight Duel
"One of Hallownest's five greatest Knights and defender of the Queen’s Glade. She was driven mad by her Queen lost and the garden overrun. Still she retains her honour, offering fair challenge to the Hollow Knight: Nail against nail. A duel to the death. "

Unfortunately, the duel did not make it into the game, but the corpse of the White Knight can be found in front of the hiding place of the White Lady. This is most likely the Great Knight Dryya.

Tyrant's Fist
(Possibly an earlier version of Desolate Dive)

This ancient, royal magic allows you to focus energy into your fist and slam it down into the ground, releasing a shockwave that blows away foes and can even rupture the earth you stand on!

Backstepping
Additional movement option that did not make it into the game. Resembles the Dash ability but in the opposite direction and with a decreased distance.

Swimming
Another movement option that allowed the player to swim under acid which was possibly scrapped for Isma's Tear. As well withing the game there is an unused room resembling the room which Unn can be found that has a layout designed for swimming through.

The Forest of Bones
(Possibly what ended up being Ancient Basin)

"The Bone Forest is further into the game than other areas we've shown so we don't want to spoil too much! But we will say it's a gigantic area of the game, with plenty of routes you can take through it and hidden secrets you can find if you brave the heat and the strange creatures who clad themselves in the bones of dead giants."

Dream Diving
By the looks of it, originally the Dream Nail was able to open up the minds of NPCs and allow the player to enter their dreams:

"During your quest through Hallownest, you'll find an ancient, bizarre artefact called the Dream Nail. Using the Dream Nail, you can slice through the conscious layer of a being's mind and access the "Dream Well," a deep space containing a bug's hopes, fears and secrets. Terrible nightmares and unique challenges will test you as you search for the core of the dream, but persevere and you'll uncover startling revelations and claim precious treasures that can't be found anywhere else. Dreams will fit the personality of each character and may even reveal some surprising secrets they have hidden away. These dreams will often involve unique twists on the Hollow Knight gameplay, such as challenging you to escape a horde of invincible flying nightmares or defeat a group of creatures without your nail. The Dream Nail is a mysterious weapon  with hidden uses, and inquisitive players will find dreams hidden in the strangest of places."

Snail Village
Little is known about the Snail Village other than it made an appearance in the Weird and Wonderful World Trailer. Some of it's assets can still be found in-game.

Mushroom NPC
Resembling a Shrumal Warrior holding a staff with a impaled Lightseed, it was probably cut due to a change to fungal creatures making to only be able to communicate through spores.

Giant Spider
Unsure whether a Boss or NPC. It's design and location does not indicate that it was affiliated with Deepnest, and it also predates the reveal of Deepnest.

Charms
In the reveal of the charms system, an image showing various charms was posted on the developer's website. Some of these charms made it into the game, while a few others didn't, and have so far been left unnamed.