Horned Serpents Spawn Theory Explained!


What are Horned Serpents? Why do they only appear in certain regions? With the help of PokeFodder and XpectoGO, I have a theory.


Horned Serpents Mystery Overview

Since the launch of the Harry Potter: Wizards Unite game on June 21, 2019, the mystery of where Horned Serpents spawn has been at the tip of our wands the entire time. Many Witches and Wizards have them in their neighborhoods and many Witches and Wizards want them in theirs!

A Horned Serpent Encounter on Oahu, Hawaii

None of this comes as a surprise since the Horned Serpent was the only Emergency Threat Level Oddity Trace prior to the release of Dragons at Wizards Unite: Fan Festival in Indianapolis, Indiana. Returning one of these Oddities will reward you with 1000 Wizarding XP when using a Baruffio’s Brain Elixir.

The problem for the last few months has been that some of us have never seen horn nor scale of this magical creature in our regions. We are pleased to announce that we may know why.

First, let’s discuss a historical overview of Horned Serpents, with information from both Pottermore and the book Fantastic Beasts and Where to Find Them.

Horned Serpents, A History

Horned Serpents have been found the world over throughout history. After being hunted to near-extinction by Witches and Wizards in Europe and the Far East for use in Potion-Making, the largest numbers today are said to exist in North America.

Horned Serpents have physiological traits consistent with their name. They are large snakes with horns on their head. Some species of the Horned Serpent have a jewel on their head, as well. This jewel is said to have magical properties that grant invisibility and flight, adding to their usefulness for Witches and Wizards.

A Horned Serpent, Poised to Fight

Isolt Sayre, Founder of Ilvermorny School of Witchcraft and Wizardry, is said to have befriended a Horned Serpent she met at a creek at the foot of Mt. Greylock, Massachusetts in 1620. This would later be the site for the great North American School of Magic, and the Horned Serpent would be chosen by its Founder as one the four Houses of Ilvermorny. Isolt Sayre and her husband later went on to craft the first American-made wands using shards from a Horned Serpent horn as its core for their adopted sons Chadwick and Webster.

Horned Serpents are said to make their homes near bodies of water. Many Native American tribes associate the Horned Serpent figure with water, rain, lightning, and thunder.

Horned Serpents Mystery Continued

Horned Serpents have been sought after for their value throughout the ages, and they are still hunted by present-day Witches and Wizards in Wizards Unite. Their presence where they dwell is known and their absence is felt even more. The question immediately asked itself: why didn’t Horned Serpents spawn everywhere?

Perhaps the most complaints about this subject came out of Southern California. Witches and Wizards in places like Los Angeles, San Diego, and the Inland Empire do not see Horned Serpents outside of a very rare statistical spawn. One player named Sara from Facebook found a single Horned Serpent in Riverside, California on Global Launch Day in June. The rest of the player population in Southern California and places with similar climates cried out for Horned Serpents. Their Oddity Registry pages sat at zero seen and zero returned unless they were fortunate enough to travel outside of the region.

Many theories were put forward regarding the properties of the areas without Horned Serpents. Presence of rainy weather, proximity to bodies of water, humidity levels, and temperature were all discussed and are still claimed by many today. Each of these notions attempted to explain the presence or lack of Horned Serpents, but often one theory would contradict the next or wouldn’t hold up against large-scale location data.

So despite everyone knowing the problem itself, we knew very little about it. We knew that when a Horned Serpent spawned in a location they did so at Dusk and Dawn. In Wizards Unite, Dawn occurs an hour on either side of a player’s local sunrise. Dusk occurs an hour on either side of a player’s local sunset. If you had Horned Serpents in your area, this is when you would find them. Everything else to be known about these creatures was anyone’s guess.

However, these theories and ideas were closer than they might imagine to the truth, as you will read shortly.

A Light In Dark Places

The complaints and theories around where Horned Serpents did or didn’t spawn have been treading water since late-June 2019 until some insider news was broken by Wizards Unite YouTube channels PokeFodder and XpectoGO after a discussion with Mary Casey, Executive Director of Product at WB Games.

The topic of Oddity spawns came up, specifically the spawn conditions for the Horned Serpent in places like Southern California, and she confirmed that there are no accidents with Oddity spawns in Wizards Unite. Oddity Encounters for Witches and Wizards playing Wizards Unite are based on canon. That is to say that the time of day, the frequency of, and the location for Oddity Encounters are based on canon from the Harry Potter Universe. Mary Casey lists her sources of canon as the seven books of the Harry Potter series, Fantastic Beasts and Where To Find Them, and Quidditch Through The Ages. There was a tenth source but she did not divulge the title.

Watch their videos here:

This is a very big revelation. The revelation that the answers to our questions regarding Oddity Encounters, and more importantly why we don’t see Horned Serpents everywhere, could be gleaned from the sources that so many of us already know and cherish. We also learned that Wizards Unite did not operate under the same biome data as Pokémon GO as has been widely assumed.

This is where I entered the scene.

The Horned Serpents Theory

I watched the videos released by YouTubers PokeFodder and XpectoGo detailing this relationship between sources of Harry Potter canon and Oddity Encounters. I felt like I could solve this riddle of why I don’t get Horned Serpents at my home in Los Angeles. After all, I do get them when I travel to places like South Carolina, Nebraska, Hawaii, and Indiana, but I didn’t get them when I was home in California or in nearby states like Arizona or Nevada.

As we read above, the Horned Serpent dwells near bodies of water, like in the story of Isolt Sayre finding her serpentine friend near a creek in Massachusetts. I tested proximity to bodies of water and that was very quickly proven wrong. I live near the beach so I knew it couldn’t be proximity to water. The Pacific Ocean is as large a body of water as you are going to find and yet, no Horned Serpents spawn for Southern California.

There are plenty of mapped bodies of water in Wizards Unite in these areas that are seeing no Horned Serpents to comfortably say that this is not the only factor. Bodies of water may be hot spots in regions that already have the Horned Serpents, but it is not the determining factor.

Was the Horned Serpent Encounter tied to rain? It has rained in Los Angeles and the Inland Empire since Global Launch, and yet we still didn’t see any Emergency Level Oddity Traces lighting up our screens at dusk or dawn. It couldn’t be rain.

I compared temperatures between locations, and that also did not have any useful correlation for the presence of Horned Serpents.

When I looked into humidity theories, I stumbled across the Köppen Climate Classification. You can read more details on it here. The Köppen Climate Classification details each region with a three letter code that describes the climate in easy-to-compare terms. For example, Los Angeles, California has a Köppen Climate Classification code of Csa. That means that Los Angeles is warm and temperate, with rain in the winter and relatively no rain in the summer.

I then looked up Big Bear Lake, California. This is the nearest confirmed location for Horned Serpent Encounters for Los Angeles and the Inland Empire. The Köppen Climate Classification for Big Bear Lake was Csb which means warm and temperate, with more rain in the winter than the summer. Yes, you read that right, Los Angeles and Big Bear Lake are pretty much the same climate even though one is Csa and one is Csb.

There are more than one difference between these climate codes, but there is one very easily identifiable difference.

Annual rainfall.

Horned Serpents Data

Los Angeles receives an average of 15 inches (381 mm) of rainfall per year. Big Bear Lake receives an average of 20 inches (508 mm) of rainfall per year.

I quickly started searching annual rainfall data for places that experience Horned Serpents and places that do not.

San Diego, California does not get Horned serpents, and they have an annual rainfall of 12 inches (305 mm) per year.

Indianapolis, Indiana does experience Horned Serpents, and they have an annual rainfall of 42 inches (1067 mm) per year.

Colorado Springs, Colorado has an annual rainfall of 18 inches per year, and Dillon, Colorado has an annual rainfall of 20 inches (508 mm) per year. Colorado Springs does not have Horned Serpents, but Dillon, Colorado does.

The cutoff for Horned Serpent Encounters appeared to be at 20 inches (508 mm) of annual rainfall for an area.

I reached out to PokeFodder and XpectoGO on Twitter with my findings. We spent the evening tossing locations back and forth, comparing the Köppen Climate codes and the annual rainfalls to Horned Serpents spawn data in their YouTube comments, and considering formulas to explain sightings.

With very little variation, each location fell in line with the theory. We expanded the request for location-based Horned Serpents spawn data to Facebook and Reddit. The data was fairly clear. Regions with greater than 20 inches (508 mm) of annual rainfall saw Horned Serpents and regions with less than 20 inches (508 mm) of annual rainfall did not.

There were a few anecdotal exceptions which prompted us to consider an active rain multiplier when the in-game weather indicates rain. For example, Tucson, Arizona has an annual rainfall of 12 inches (305 mm) per year and does not see Horned Serpents regularly. However, player reports from the area following a monsoon said that they received Horned Serpents that evening and only that evening at Dusk. Other areas with less than or equal to 20 inches (508 mm) of annual rainfall also reported Horned Serpent sightings during or after heavy rain weather.

There are still things we do not understand about this game mechanic. The presence of a rain multiplier for when in-game weather indicates rainy is suspected but ultimately unknown. There are also places like Pasadena, California who have an annual rainfall of 21 inches (534 mm), but are surrounded by a region with annual rainfall data that is less than 20 inches (508 mm). Pasadena hasn’t experienced any Horned Serpent spawns.

Will places like Pasadena experience Horned Serpents after a heavy rain? Will Los Angeles start seeing regular Horned Serpent Encounters when we enter the rainy, winter months? Only time and diligence will tell.

Horned Serpent Anecdote Data Based On Rainfall and Player Reports.

Weighing of the Wands (In Conclusion)

After sampling over one thousand anecdotes from Witches and Wizards around the world, and then comparing the various locations to our findings, we have reached the conclusion that Horned Serpent Encounters at Dusk and Dawn are based on annual rainfall for a location, and may be influenced by an in-game multiplier when an active rain condition is present.

If the Encounters are not based on annual rainfall, then they appear to be based on a dataset that directly correlates to annual rainfall. The hundreds of locations observed with this theory only saw a few contradictory anomalies. That is why we are comfortable treating this information, at the very least, as a useful prediction tool for determining if a location you live in, or will be traveling to, will have Horned Serpents.

To capture everything we have proposed, I’ll repeat the theory here.

If your region experiences an annual rainfall of greater than 20 inches (508 mm), then you should regularly have Horned Serpent spawn for you.

If your region experiences an annual rainfall of less than 20 inches (508 mm) then you should not have Horned Serpent spawn for you.

If you live in an area with less than 20 inches (508 mm) of rainfall annually, but there is a heavy rain condition, you may see some isolated Horned Serpents spawn during Dawn and Dusk for that day.

Make sure to check out XpectoGO’s and PokeFodder’s videos on the subject:

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Geovana Mariano
Geovana Mariano(@geovanamariano)
2 years ago

this teory makes sense, here where i live in Brazil we have a annual rainfall of more then 500mm and the spawn of horned serpents is pretty common

Jeff Lanam
Jeff Lanam(@jefflanam)
2 years ago

I never saw Horned Serpents until I went to Santa Cruz, CA (annual rainfall 33in). I saw two at the Costco store and another later the same evening.

Geoff Nelson
Geoff Nelson(@geoffnelson)
2 years ago

I’m in Salt Lake City. Many people here haven’t found Horned Serpents. I’ve found 10 so far, and all of them have been near the Hospital on the University campus. If this is based on some GPS based map of the annual rainfall, then it could explain why most people in SLC itself haven’t found any, but if you go a ways up the side of the mountain you enter a region that does cross that threshold. As far as I’m aware in SLC you can only find them on the side of the mountain on the east edge of… Read more »

Patrick OKeefe
Patrick OKeefe(@patrickokeefe)
2 years ago

I live in Aurora CO, neighboring Denver which is listed for 9 inches annual rainfall but I’ve caught 8 horned serpents, and never after a big storm

Geoff Nelson
Geoff Nelson(@geoffnelson)
2 years ago
Reply to  Patrick OKeefe

I think we need to find the source the game uses for this. If I look at Aurora, CO on weather-us.com it shows 18.4″ annual.

Maybe Aurora would be a good place to look at when trying to find where the game gets its info from.

Alex Daedric
Alex Daedric(@alexdaedric)
2 years ago

I live in Lancaster, UK, with approximately 43″ of rain annually

I’ve only seen the horned serpent 3 times, one after the other, a few days after the game was released

I play every day, for extended periods of time, at all times of day, and I’ve not seen one since, so I’ve given up.

Mauricio Aponte
Mauricio Aponte(@mauricioaponte)
2 years ago

I live in Bogotá, Colombia, and I see Horned Serpents almost everyday. We have a yearly average amount of precipitation of 37.8″ (960.1 mm).

2 years ago

Great info, we have them coming out our ears in Melbourne, Australia.
Can you do this for the other oddities as I struggle to find Brown Centaurs locally.

Chris Gusnowsky
Chris Gusnowsky(@chrisgusnowsky)
2 years ago
Reply to  sirfoxey

I find that surprising! Brown Centaurs are the only oddity that we see 24/7 here. We see so many (I have seen 206, for example) that I did not think there were any conditions on them at all, and that they were the one universal Oddity.

Chris Gusnowsky
Chris Gusnowsky(@chrisgusnowsky)
2 years ago

We get serpents like CRAZY here (when I ranked up the page serpents were the first thing that I was able to place, as I see 5-6 per day without even making an effort), and we have less than 20 inches annual rainfall here (we average 18 inches annually). We do live near a small man-made pond, for what that’s worth.