Hilichurls are always found wearing a mask and speak the Hilichurlian language. Some suggest that they wear the masks because they don't like seeing their reflections in the water. Despite their general hostility towards outsiders or humans and a less than optimal lifestyle, Hilichurls are also intelligent for their standards, as a few use tools and Slimes, scavenge, and even engage in agriculture, albeit limited to raising livestock due to the race's general dislike of vegetables. They have a fairly impressive, albeit archaic architectural style, the construction or purpose of them unknown. Aside from the practical use of tools, some Hilichurls such as the Pyro Grenadiers can destroy four training dummies at once with a precise throw.
They appear to not have an Archon or God governing them, rather they rely on the most strongest and ferocious among them to lead the tribe. The Lawachurls whose name is derived from the Hilichurlian way of respectfully addressing a king or ruler are revered by younger Hilichurls. Despite their status as a role model or "king" for the smaller hierarchy, Lawachurls ironically prefer being solitary.
Hilichurls appear to have a reliable social network, as some Hilichurls are friends with others despite being extremely far away from each other. Like humans, Hilichurls can live in a myriad of environments and acclimate themselves accordingly.
Many Hilichurls are also affiliated with the Abyss Order, as the Abyss Mages are able to speak fluent Hilichurlian. Unlike humans, who usually have to rely on a Vision or science to manipulate the elements, some Hilichurls are naturally capable of doing so, such as the samachurls — why or how is unknown. That said, Hilichurls typically stay away from areas with high elemental concentrations, as it places a great burden on their body.
They are one of the first types of monsters and enemies encountered in the game along with the Slimes.
While Hilichurls can be found all over Teyvat, some of them in small tribes, there are three prominent tribes, all of whom can be found in Dadaupa Gorge. A tribe's composition tends to vary, usually containing a large amount of normal hilichurls. Most tribes also have Samachurls, who are the oldest of the Hilichurls and often lead the tribes.
Some tribes may not have Samachurls, which is the result of younger, stronger members overthrowing them. These tribes are most likely led by Mitachurls and are far more aggressive. Even fewer tribes are led by Lawachurls, as the few that are around prefer solitude and dislike the reverence the younger members give them.
The Sleeper Tribe Hilichurls are known for napping whenever possible. They are particularly skilled in making beds, as it is rumored that their animal-skin beds are incredibly soft.
The Meaty Tribe Hilichurls are known for making sacrifices on a regular basis. They pray for meat every day and highly value strength. Apart from building huge altars, they possess a massive cooking pot and a huge arena for members of the tribe to spar.
The Hilichurls of the Eclipse Tribe are said to be extremely mysterious; all Hilichurls of that tribe know how to draw an eclipse symbol. It is rumored that the Dada Samachurls of this tribe know the reasoning behind this.
- The name hilichurl is likely derived from the English words "hill" and "churl."
- Hilichurls may be inspired by a type of oni called Amanojaku (Japanese: 天邪鬼 "heavenly evil spirit"). It is also called a jaki (Japanese: 邪鬼) in some branches of Buddhism. These creatures are also the inspiration for the main enemy type in the game Ōkami, which also wear masks.
- Although it seems that Hilichurls have an affinity for remnants of the past, there is no hint about their connection with the lost civilization.
- A tribe in Dadaupa Gorge called the Eclipse tribe, worships an object that appears to represent an eclipsed sun. This object might be a reference to the now fallen Eclipse Dynasty in Khaenri'ah.
- Hilichurls seem to recite poems or songs, according to Jacob Musk. These range from expressions of grief, festivity, and so on.
- Certain missions feature friendlier, non-hostile Hilichurls.
- An unarmed Hilichurl will throw rocks with their left, suggesting that it's supposed to be also used by Hilichurl Fighters (who wield clubs with their right).
- If a Pyro Hilichurl Grenadier attempts to dig out a slime in shallow water, they will humorously show up empty handed while looking on with confusion. Cryo Hilichurl Grenadiers can successfully do so, however, and interestingly, the Cryo slimes they dig up appear to be Frozen.
- In the manga, Hilichurls during the time of Vennessa had different appearances compared to their present-day counterparts. They were depicted with more colorful masks, and could be seen using traditional bows instead of the crossbows now wielded by Hilichurl Shooters. Notably, there was also a kind of flying Hilichurl with bat-like wings that is not known to appear in any other media.
- Samachurls interestingly make noises when moving; panting sounds when running, and singing when walking. They are the only Hilichurl variant observed doing this.