Leoric's Shinbone is a miscellaneous crafting material in Diablo III, it is used to construct the
Leoric's Shinbone
You can farm it in both Adventure Mode and Campaign Mode. In Campaign Mode, you need to start the game in Act I, Quest 9: The Imprisoned Angel, Part 2: The Cursed Hold. Port to the Leoric's Manor waypoint.
As for the recipe, you'll need to kill Izual in Act 4 to get your hands on it, although you might have to do this a few times as it's not a guaranteed drop. When you've got the recipe and all the ingredients you need, head to Haedrig the Blacksmith, teach him the recipe, then craft the Staff of Herding.
Once inside of Leoric's Manor locate the northern room (use your in-game map to check your orientation); it is the room to the "top-right" of the stairs leading to the Coven's meeting. If the item is in the room, you will see wood in the room's fireplace. Just click on it and you will get Leoric's Shinbone.
The Black Mushroom is a reagent for the Staff of Herding which grants you access to the secret level Whimsyshire. This item is found in the Cathedral Level 1 in Act I. It doesn't always spawn but if you want to farm for it, take the Waypoint to Cathedral Level 1.
The Menagerist Goblin, Napper of Pets is a variant of the Treasure Goblin in Diablo III, introduced in patch 2.4. 1. It can only appear in Adventure Mode, usually in open world (but on rare occasions, can spawn in Nephalem Rifts as well).
Whimsyshire is a Secret Level, or secret land, in Diablo 3. When you enter the Secret Level of Whimsyshire a Feat of Strength along with a Banner and Sigil are unlocked. You can run the Whimsyshire level as many times as you want and you will get the In The Land Of Killer Unicorns achievement for finding it.
Put the Staff of Herding in your inventory (it's not necessary to equip it). Note that the staff is permanent and it is not consumed; in fact, you can replay the Whimsyshire level as many times as you like. Whimsyshire can be accessed in both Adventure and story mode.
When she spawns, she has a rare chance to drop the Gibbering Gemstone. The item will be account bound as soon as it drops. There is also a bounty quest to kill Chiltara, which may make finding the Huntress easier. Gemstone drop rate is approximately 5%, but as of patch 2.0.
Wirt's Bell is a miscellaneous crafting material in Diablo III, it is used to construct the Staff of Herding which is necessary to access Whimsyshire. It has an Item Level of 1 and requires a character level of 1.
The Black Mushroom is an item used to craft the Staff of Herding, which can be used to gain access to Whimsyshire. It can be found on Level 1 in the Cathedral (Normal difficulty).
The Nightmarish Staff of Herding was a craftable staff in Diablo III. It was needed to access Whimsyshire on Nightmare difficulty. As of version 2.0, any version of the Staff of Herding will grant the player access to Whimsyshire on any difficulty, so it is no longer necessary nor possible to upgrade the staff.
Leoric's Crown is a Legendary helm in Diablo III. It requires character level 8 to drop (but the Skeleton King will drop it as of level 5 the first time he is killed in Campaign Mode, reset by starting a new Campaign).
If you are using Kadala to try and get a lv70 Leoric's Crown for your Monk (and don't need a %skill roll on it), powerlevel a Demon Hunter and spend your Blood Shards on that character.
Leoric's Shinbone is a miscellaneous crafting material in Diablo III, it is used to construct the Staff of Herding which is necessary to access Whimsyshire. It can sometimes be found in the fireplace of Leoric's Manor in Act I. The fireplace is located at the end of a hall on the right side the manor in the entry area.
The legendary effect works even if equipped on Followers. The bonus gem type is always based on the gem socketed in the player's helmet, even when the crown is equipped in the Kanai's Cube or on a follower.
Whimsydale is a unique location in Diablo III that can only be accessed by killing a Rainbow Goblin. It uses the Whimsyshire tileset, and is overall identical to it. This location was added in patch 2.1.
Spectrum is a Legendary sword in Diablo III. It requires character level 30 to drop, and can only be obtained from unique monsters in Whimsyshire or Whimsydale, at a very low chance. For example, it can drop from the Pink Rainbow Unicorns.
Can be found in Adventure Mode and is made easier to gather when the Bounty in Dahlgur Oasis is for clearing the Mysterious Cave Level 2 of all enemies.
They drop from Princess Lilian in Whimsydale (not in Whimsyshire).
Unihorn is a non-combat pet in Diablo III, added in patch 2.4. 1. It drops from Menagerist Treasure Goblins. It's like a horse, but pointy.
Leoric's Regret is a miscellaneous Legendary crafting material in Diablo III and can be combined with other demonic body parts to create a ring or amulet of incredible power.