If you’ve spent more than five minutes in New Eridu, you’ve seen them. The seven-foot-tall bear managing a construction site. The elegant wolf-man serving tea. The teenager with a massive, serrated shark tail dragging behind her at the grocery store.
In the world of Zenless Zone Zero Thiren characters aren't just "furries" or "cat-girls" thrown in for aesthetic flair. They are a fundamental, integrated part of the city’s social fabric. But despite how common they are, the game is surprisingly quiet about where they actually came from. Honestly, it’s one of the biggest mysteries in the lore.
Some players assume they are a product of Hollow corruption. Others think they’re just humans with high-tech cosplays. Both of those guesses are basically wrong.
What Exactly Is a Thiren?
The word "Thiren" is the in-universe term for any humanoid being that possesses animalistic traits. They aren't monsters, and they aren't "mutants" in the way we usually think of them. They are citizens. They pay taxes, they run businesses, and they have the same legal rights as baseline humans.
You’ll notice two distinct "vibes" when looking at Zenless Zone Zero Thiren designs.
First, you have the Beast Thirens. These are the characters who look almost entirely like animals walking on two legs. Think of Ben Bigger (the bear) or Von Lycaon (the wolf). They have fur, snouts, and paws, yet they speak human languages and live human lives.
Then you have what the community often calls "Half-Thirens" or human-dominant Thirens. These characters, like Seth Lowell or Ellen Joe, look 90% human but sport specific animal appendages—usually ears, tails, or in Ellen’s case, a massive shark tail and literal shark teeth.
It’s Not About the Hollows
One of the most common misconceptions is that people "turned" into Thirens because of the Hollow disaster. This isn't true. We know this because of Ben Bigger.
During one of Ben’s trust events, he talks about an old-world movie featuring Bear Thirens as astronauts. This confirms that Thirens existed long before the first Hollow ever appeared. They were part of the "Old World" civilization, even participating in space programs.
While the game hasn't explicitly dropped a "Thiren Origin Story" document yet, the prevailing theory among lore hunters is that they are either a naturally occurring subspecies of humanity or the result of ancient genetic engineering that happened so long ago it’s now just a normal part of biology.
The Biological Quirks No One Talks About
Being a Thiren in New Eridu isn't just about looking cool; it comes with some weird biological baggage.
Take Ellen Joe, for example. In her lore snippets and trust interactions, it’s mentioned that her shark tail grows continuously throughout her life, much like a real shark’s teeth. It’s heavy, it’s cumbersome, and it probably makes buying pants a total nightmare.
Then there’s the Ether Aptitude.
Statistically, Thirens in the Zenless Zone Zero universe seem to have a higher natural resistance or affinity for Ether compared to baseline humans. This is why you see so many of them working as Agents or in high-risk zones like the Belobog Heavy Industries construction sites. They can handle the "pressure" of a Hollow slightly better than your average person, though they aren't immune to turning into Ethereals if they stay inside too long.
Instinct vs. Intellect
There is a constant tension between a Thiren’s human mind and their animal instincts.
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- Von Lycaon is the perfect example of this. He is the ultimate gentleman, yet he gets visibly embarrassed when his tail starts wagging uncontrollably because he’s happy.
- Nekomata (Nekomiya Mana) leans into it more, often displaying feline agility and a literal craving for fish, though she also uses "cybernetic" enhancements to augment her natural Thiren abilities.
- Seth Lowell has ears that twitch and react to sound independently of his conscious control, which is a detail many players miss until they see him in a cutscene.
Social Standing and "Speciesism"
Is there discrimination in New Eridu? Kinda, but it’s subtle.
Unlike many fantasy worlds where "beast-folk" are relegated to the fringes, Thirens are everywhere in New Eridu's power structures. You have Thirens in the police force (PubSec), in massive corporations, and in elite maid services.
However, you’ll notice that certain types of Thirens seem more "rare" than others. For instance, Tiger Thirens are mentioned in the lore as being nearly extinct or extremely secluded. Most of the Thirens we see in the city are cats, bears, or dogs. This suggests that while the city is inclusive, the history of Thiren-kind is full of migrations, wars, and population shifts that we’ve only scratched the surface of.
Every Thiren Character We Know So Far
To keep track of the growing roster, here’s a quick breakdown of the prominent Thirens currently in the game or lore:
The Heavy Hitters (Beast Thirens)
- Ben Bigger: A massive Brown Bear who is surprisingly good at math and serves as the backbone of Belobog Heavy Industries.
- Von Lycaon: A Wolf Thiren and the lead butler of Victoria Housekeeping. He’s basically the definition of "cool under pressure."
- Big Daddy: A Boar Thiren who leads the Sons of Calydon. He’s as tough as he looks.
The Hybrid Types (Human-Dominant)
- Ellen Joe: A Shark Thiren. Her design is unique because she’s one of the few non-mammalian Thirens we see in a major role.
- Nekomata: A Cat Thiren (specifically based on the Nekomata folklore, hence the split tail).
- Seth Lowell: A Feline Thiren (Lynx/Maine Coon) who works for Public Security.
- Jane Doe: While she looks human, she is a Rat Thiren. Her "tail" is often debated as being a prosthetic, but her mannerisms are pure rodent.
- Hoshimi Miyabi: A Fox Thiren. She’s the leader of Section 6 and is widely considered one of the most powerful beings in New Eridu.
Why Does This Matter for Your Gameplay?
Understanding the Zenless Zone Zero Thiren lore actually helps you appreciate the character kits more.
HoYoverse is very intentional with how they animate these characters. A Thiren’s combat style is almost always an extension of their biology. Lycaon uses powerful kicks because wolves are pursuit predators with immense leg strength. Ellen uses her tail as a massive bludgeoning weapon. Ben uses his sheer bulk to parry attacks that would crush a normal human.
When you’re building your team, you aren't just looking at "Ice" or "Physical" types—you’re looking at how these biological traits manifest in their "Ex" specials and ultimate moves.
Looking Ahead: What We Still Don't Know
There are still massive holes in the story. We don't know if a human and a Thiren can have children, and if so, what that child looks like. Does the Thiren gene just "pop up" randomly, or is it strictly hereditary?
We also haven't seen many bird or reptile Thirens. Are they in a different city? Or did they not survive the rise of the Hollows as well as the mammals did?
Actionable Next Steps for Lore Hunters:
- Check the "Trust" Events: If you want the real dirt on Thiren biology, stop skipping the dialogue during coffee or movie hangouts with Ben and Lycaon. They drop massive hints about their physical limitations.
- Read the Item Descriptions: Some of the "W-Engine" descriptions and specialized gear items mention Thiren-specific medical needs or physical adjustments.
- Watch the Background NPCs: Lumina Square is full of Thiren NPCs that aren't playable. Looking at their designs tells you a lot about the "average" Thiren vs. the "Elite" ones we play as.
The world of New Eridu is built on the idea that "normal" is a relative term. Whether you're a human or a seven-foot bear, as long as you can survive the Hollows, you've got a place on Sixth Street.
Actionable Insight: Keep an eye on future "Section 6" story updates. Since Hoshimi Miyabi belongs to a famous Thiren lineage, we are likely to get a massive lore drop regarding Thiren history and their role in the Old World very soon.