For years, experienced players eager for a challenge have asked Cipsoft: “Give us a challenging mount, like some in the past, and not just an item-clicking mount,” and well, we confess that a good job has been done.
[Disclaimer: This post does not prove the exact functioning of this creature, due to the difficulties of testing we have decided to deliver the strong evidence and help Tibians have more motivation in their searches].
Well, after clarifying that what I'm going to say here is based on my own observations, experiences and analysis of all the data obtained, let's get into the basics of this creature. The Mystic Jaguar is a tameable, immortal creature with a quick disappearance time, and its appearance can take place in different places in this floor (remembering that the entire area to the west of the central corridor and statue - on the left - has already had records of Mystic Jaguar appearances), focus on checking all the corridors, rooms and creating the route that satisfies you the most. Remember that this is what has been recorded, but there is a possibility that the spawn could happen anywhere on that floor, including the northeast and east sides of the central corridor.

Mechanics of the Spawn and Despawn of the Mystic Jaguar (according to evidence)
Its spawn (or the possibility of spawn) is linked to the server boot time (the time at which many features that have timers start to count), if you have any doubts check out this topic. Similarly to the Albino Dragon, the Mystic Jaguar's spawn timer doesn't seem to start exactly at server boot, but with an initial interval of 10 minutes, after which a fixed 15-minute counter is applied throughout the day, until the next server save. So, in other words, every 15 minutes throughout the day there is the possibility of this creature spawning. If the server boot happens at minute 04 (10:04 CET) on your server, the first possible spawn time would be 04 + 10 = XX:14, and the following at XX:29, XX:44 and XX:59.
In a standard way, by taking the time of the server boot and using only the minutes it occurred, you will get 4 check times per hour and follow the cycle:
Check 1: Server boot minute + 10.
Check 2: Server boot minute + 10 + 15.
Check 3: Server boot minute + 10 + 15 + 15.
Check 4: Server boot minute + 10 + 15 + 15 + 15.
The question you might be asking: “If the chance is every 15 minutes, why don't we see the Mystic Jaguar very often?”, and the answer is simple, its probability must be very low, from statistics collected our estimate is that the chance is 0.1% (1 in 1000 possibilities).
If the chance of spawn is every 15 minutes, following the rules already mentioned, there are between 95 and 96 chances of it spawning over 24 hours, the real average of approximately once every 10 days.
The Mystic Jaguar follows the logic of the Albino Dragon, in that when the time for the next spawn chance is up it disappears, so it is estimated that the time a Jaguar is accessible in the game is exactly 15 minutes (this largely explains why there have been so many reports of this creature disappearing).
Data collected and evidence of known mechanics
We'll provide you with objective data that backs up what we've mentioned in this post:
On a no-patch day (with server boot at 10:03 CET), a player (A) was actively searching for the jaguar with checks every 15 minutes, but at minute xx:25 ended up leaving to refill his character. Another player (B) went to Iksupan to check for the Jaguar and found it when he arrived at minute XX:33. His spawn occurred in the window between minute 25 and 33. It is estimated that in this case the spawn occurred in minute 28. Photo below of the moment of the meeting, thank you for your contribution with the photo of this specific case.

On a no-patch day (with server boot at 10:04 CET), a player (the author of this post) was actively searching for the jaguar at different intervals in order to understand how it worked. A check was made at time XX:55 with no evidence of the jaguar, and when a check was made at minute XX:01 the jaguar was found in the position in the photo below. Its spawn occurred in the window between minute 55 and 01. It is estimated that in this case the spawn occurred at minute 59.

On a no-patch day (with server boot at 10:04 CET), exactly one day after the previous entry above, a player (the author of this post) was searching for the jaguar at intervals of between 10 and 15 minutes. A check was made at minute XX:32 without any sign of this creature, and on repeating the check at minute XX:46 it was found as shown in the photo below. Its spawn occurred in the window between minute 32 and 46. It is estimated that in this case the spawn occurred at minute 44.

On a no-patch day (with server boot at 10:03 CET), a player (A) (who had already tamed the Mystic Jaguar) found this creature at approximately minute XX:24 when he was doing a single check at the location (without having done any others before), he tried to contact other people so that they could tame this creature, but only at minute XX:26 did another player (B) confirm that he was going to Iksupan to try to tame it, before he could arrive (at approximately minute XX:28) the creature disappeared in front of the player who had initially found it (A). There is no way of determining when the jaguar appeared in this isolated case, but by analyzing all the cases/evidence it is estimated that its spawn occurred at minute XX:13, having completed 15 minutes in the spawn at exactly minute 28 when it disappeared.
On a no-patch day (with server boot between 10:03 CET and 10:04 CET), a player found the jaguar after checks between 8 and 10 minutes apart. We can't confirm the exact time of the encounter, but it's shortly after minute 14 (according to the open World chat window). Assuming he found it in minute 16 (an average of the time between messages), his last check would have occurred in minutes XX:06-XX:08. According to pattern analysis of the other appearances (analysis below) it is estimated that the Mystic Jaguar spawn occurred at minute XX:13/XX:14.

All the reports lead to a common point, we had to analyze them in order to establish a pattern, a rule that would explain all the cases, and we started with the report of the jaguar's disappearance at approximately minute 28, it was 25 minutes out of server boot (the main starting point for investigations of this type).
The case involving two players in which one had left to refill, in our first data recorded in this topic, made it possible to reduce the window of spawn possibilities to a period of just 8 minutes (between minute 25 and 33), considering that the spawn would also be displaced in this case by 25 minutes of the server boot, would result in the Mystic Jaguar's moment of spawn for minute 28, compatible with what was observed. This brings us to something: the same minute that one was born was the minute that another disappeared, if you consider this reasoning to be valid.
We came across the case where the author of this post found the Mystic Jaguar at minute 01, on a day when the server boot occurred at minute 04. The last check before the encounter had been at minute 55, giving us a window of only 6 minutes (between minute 55 and 01). Considering an interval of 25 minutes, as was analyzed until then, would lead us to 2 fixed intervals of 25 minutes, and a result that the Mystic Jaguar should have been spawned at minute 54 (which is not true), so the hypothesis of a fixed interval of 25 minutes was discarded at this point.
With the appearance of a Mystic Jaguar the following day, between the checks at minutes 32 and 46, it became clear that the fixed interval time was shorter than initially thought. The server boot that day also took place at minute 04, and was very close to an already confirmed time (25 minutes after the server boot). Considering the previous possible spawn of minute 29 (minute 4 + 25 minutes interval), the interval between this new spawn would have been between 03 and 17 minutes.
It was at this point that the idea came to us that the Mystic Jaguar could behave exactly like the Albino Dragon (because they were added to the game at very close times). So we dropped the initial 25-minute interval for a single 10-minute interval, with fixed 15-minute intervals, but we still needed to apply this to all the cases we had seen so far. Considering the case of the Jaguar found between minutes 32 and 46, we decided to add 15 to the last possible spawn prior to this (server boot of minute 04 + 10 [a single time] + 15 [fixed interval] = 29), which resulted in an estimated spawn at minute 44, totally compatible with what was observed. We applied the same to the other case of jaguar appearance between minutes 55 and 01, added 15 minutes to minute 44 (previous possible spawn), and got minute 59, again compatible with what was observed.
So there was evidence of possible spawns at minutes 10+15 post server boot, 10+15+15 post server boot, and 10+15+15+15 post server boot. There was one encounter report missing at minute 10 post server boot, and it came at just the right time. The report of a jaguar encounter just after minute 14, with the last check between 8 and 10 minutes earlier, confirmed the predicted scenario. As the encounter didn't occur on a patch day, we can infer that the server boot occurred between minutes 03 and 04, so for this specific case the spawn moment probably occurred between minutes XX:13 and XX:14 (which is basically the sum of the first 10 minutes of the server boot interval). With this final piece of data, we have arrived at a hypothesis with strong evidence that deserves to be taken seriously.
Our help to the checkers
Obviously, we wouldn't just give you the details of how we believe the Jaguar works, but also a way to make it easier for you to control when you check, which is why we've also announced the creation of the TibiaLight Check-Helper. In it, as well as other check options, there is the Mystic Jaguar.

There are two ways to use this tool, whether you are logged in to TibiaLight or not. To create an account or log in to an account you have already created, look for the icon at the top left of the site. If you are logged in, your checks will be saved even if you close the page, otherwise it will reset every session. This tool does not store checks over time, so each day to start a round of checks you will need to renew the checker tab (or tabs).
There are some important parts of the tool such as:
The underlined icon in the image with the number 1 represents the text box where you must manually enter the server boot time of your server (in your time zone). To find out how to obtain this information, visit this topic. It is recommended that you always put 1 minute past the boot time, to avoid starting the check seconds before a possible spawn.
After entering the server boot time, click on the button underlined as number 3; all the tabs will start based on the server boot indicated.
There are 5 checker options in this tool, to switch between them just click on the icon of each of the creatures, the timetable panel will change accordingly.
To perform a check in the tool, simply click on the time corresponding to the moment/interval being checked. When you click on it, it will change color to green and indicate that it has been checked. If you have mistakenly clicked on the time, just click on it again to switch between checked and unchecked. It's not possible to check in the future, so if you click on times that haven't arrived yet there will be a message preventing you from doing so. When you click on a time, all previous times that have not been checked will remain unchecked and will be represented by the color red.
If you need to completely reset just one tab, click on the underlined button with the number 2. This will reset only the tab selected in the tool. If you want to reset all tabs at the same time, just click on the button underlined with the number 3.
There is a counter below each creature's tab. This countdown timer updates as the next possible check approaches, individually.
By translating the tibialight website using the language button, the tool will also be translated.
You can switch between the tool's 2 color modes on the button to the top right.
The knowledge of how it works may not mean it's easier to tame
Despite all the data presented here, the probability of a Mystic Jaguar spawning will remain the same (incredibly low), what we can improve is the efficiency with which the checks take place. As stated above, finding a jaguar can take an average of 10 days by checking all day, so as this is an unrealistic scenario, checking a few hours a day can mean a long period of searching.
Not enough, the chance of the Mystic Jaguar disappearing when using the Polished Idol of Tukh is high, with many players reporting that they have managed to tame it on the third, fourth, fifth or even sixth attempt.
Keeping the spawn creatures locked up can help, but make sure it doesn't make it difficult to see all the corners/rooms and corridors, as the Jaguar could be in the unseen spot.
Final thoughts and loose ends
In all the records analyzed (and many that were not mentioned in the post) the encounter with the Mystic Jaguar obeyed the reasoning described, no situation caused the hypothesis to be put at risk, but it is hoped that with more future records we will be able to confirm it exactly. There are curious cases, however, in which players have come across the Mystic Jaguar when carrying out just 1 or 2 checks a day, usually when they were going to kill bosses such as Ahau, Atab or Mitmah Vanguard. This is curious because there have been several examples of this and, as we've described, the chance of encountering a jaguar at a given moment in the spawn is minimal. Possibly there is a way to increase the spawn probabilities, maintaining the same spawn logic and mechanics described in this topic, but with chances higher than the estimated 0.1%.
We hope that this information and the tool will be useful in the search for the Mystic Jaguar, good luck to those who are looking for it, and to those who will be encouraged to look for it.