Laughing Skull Orcs

The Laughing Skull Orcs, or Laughing Skull clan, is an orc clan presumably led by Kaz the Shrieker and makes their home in Gorgrond. Known for their violent and bloodthirsty nature, these orcs take great pride in their clan identity and have therefore refused to join the Iron Horde. With the Iron Horde trying to destroy the Laughing Skull clan, they have allied themselves with the Frostwolf clan and the Horde to fight their common enemy.

In the past, the two clans battled against each other. Following events in Gorgrond, however, they appear to be rather close allies.

Early in their settlement of Draenor, the draenei Rangari learned from the Laughing Skulls that podlings hate fire. The Rangari Refuge in Tanaan Jungle houses several Laughing Skull refugees and guards, indicating the two factions may still be close.

According to Marrow in Beastwatch, the Laughing Skull orcs use goren teeth as tools and weaponry.

The Laughing Skull chortle whenever they collect Humerus Bones from a fallen enemy.

Warlords of Draenor
As the various clans of Draenor began uniting to begin their invasion of Azeroth, the Laughing Skulls rejected their offer, wishing to keep their freedom to kill whomever they wished. Following The Battle of Thunder Pass (quest), the Frostwolf clan chieftain, his mate , and the Horde commander make contact with the Laughing Skull shaman Kaz the Shrieker. After helping them with a goren invasion of their village, Kaz and her compatriots agree to an alliance with the Frostwolves, and by extension Vol'jin's Horde, against their common enemies. The Laughing Skull's involvement in the Gorgrond storyline splits when the player chooses either a lumber mill or an arena.

During the arena campaign, the Laughing Skull has a smaller role. Bony Xuk accompanies the player through the wastes giving quests until Get the Xuk Outta Here! when the spirits apparently play a trick on the shaman and get him killed by Gro the Uncreator. His spirit can be recruited as a follower.

During the lumber mill campaign, the clan has a comparatively larger role, where Kaz and her son Cutter join Draka in battling the botani and securing greater resources for the garrison. During the storyline, Kaz and Draka butt heads over strategy but eventually begin to respect each other. They discover an artifact that can control genesaurs and retrieve it from the hands of the botani. After an epic battle during Iyu (Horde), Kaz now calls Draka "sister" and pledges her clan and herself (as a follower) fully the Horde's cause. The Laughing Skull later aids in the assault on the Iron Approach during Strike While the Iron is Hot (Lumber Mill) (Horde).

Greater Laughing Skull Orc reputation can be unlocked by building a Trading Post at your garrison.

Tanaan Jungle
A group of Laughing Skull refugees can be found at Rangari Refuge in Tanaan Jungle, where they are under supervision by Frogan. Some scouts have been imprisoned in the but were rescued when the adventurers raided the place.

Battle for Azeroth
In time, the Laughing Skull clan joined with the other Mag'har orc clans under the command of Warchief Grommash Hellscream. As the Mag'har and Lightbound clashed, events on Azeroth would see to a new war between the Horde and the Alliance. In the midst of this, Eitrigg sought to travel to the alternate Draenor and call upon the debt the Mag'har owed to the Horde for liberating them from Garrosh Hellscream's meddling and the Burning Legion's corruption.

As the entire Lightbound army was marching towards the Mag'har, Grommash ordered for the Mag'har to follow Geya'rah and fallback to Azeroth. Thus, when Warchief Hellscream and Lantresor of the Blade charged at the Lightbound, Eitrigg activated the shard of the Vision of Time in his possession in order to return to Azeroth with his new allies. After their arrival on Azeroth, Overlord Geya'rah took her place as leader of the Mag'har and pledged the loyalty of her people to Warchief Sylvanas Windrunner and the Horde.

After joining the Horde, members of the clan like Kaz the Shrieker can be seen fighting for the Horde against the Alliance on Zandalar and Kul Tiras.

Speculation

 * Mogor led the Laughing Skull clan during the Second War, but is not shown to be connected to them in Warlords of Draenor. As the earliest reference to Mogor in the main timeline was in the Second War, it's possible he only took command of the clan around then.
 * Since the vast majority of Laughing Skull NPCs that wear masks with a red pattern seem to be individuals specialized in a particular role, such as blacksmiths, flight masters and food vendors, it's possible that a Laughing Skull's status is represented by which type of mask they wear. Though due to the Mag'har Limbflayers now within the Valley of Honor using the red patterned mask this is most likely untrue.
 * According to Kaz the Shrieker in the quest We Die Laughing! with a mask and the right incentive the clan can make anybody into a Laughing Skull. This may imply that some Laughing Skull orcs were originally from other clans and joined later on in their lives.