Taisaijin

Notes (Ranguemont Pass)

 * The average respawn time is 72 +/- 1 hours (Earth time), and every 24 +/- 1 hours thereafter. However it can vary a lot from 24~ hours up to at least 29 hours. See the Discussion page for more info.
 * Maintenance does not open the spawn window.
 * It is often thought that no Taisai can be disturbed during the respawn period, this however is not completely true. It seems that the Taisai that morphs into Taisaijin, is the only one that cannot be killed, which will effectively reset the timer to 3 days.
 * The "PH" seems to rotate through the three Taisai in the order: middle, west, east and back to the middle one. Since they do wander around, it may seem random.
 * If only Taisaijin is defeated, but the next Taisai to morph is not killed during the following 24~ hours, Taisaijin will spawn again, replacing that Taisai.
 * Because of this it's possible though unlikely for multiple Taisaijin to be up at once.
 * Aggressive towards level 75 characters.
 * Players can lose aggression when attempting to kite Taisaijin.

Notes (Nyzul Isle)

 * The Armoury Crate it leaves behind contains a ??? Headpiece, which may rarely appraise into a Spelunker's Hat.

Video
See the Video page.

Cultural Background
Taisaijin is Japanese for either "grand festival god", "king of the grand year", "grand festival", or "large age".

In-Game Background
Taisaijin is widely believed to be a joke-NM based on an in-game joke that isn't commonly known among English-speaking players. The Red Mage magic spell Refresh was introduced to Final Fantasy XI in the February 5, 2003 update.

At the time Refresh was introduced, the methods and locations for obtaining the scroll were still largely unknown. As the story goes, before the whereabouts of Refresh became known, one Japanese Red Mage claimed that he had gotten a Refresh scroll as a drop from a Taisai in Ranguemont Pass. The rumor eventually spread, and for a period of time, Taisai were being farmed constantly for the scroll. The truth is, that Red Mage lied. Refresh is not, nor has it ever been, a drop from Taisai. That Red Mage had discovered one of the actual methods for obtaining Refresh and proceeded to monopolize that source, profiting from the advantage since there was no competition for it and everyone was deceived into farming Taisais.

This incident would give rise to an in-game joke among Japanese players. When another player asked where to find a newly introduced item that no one yet knew how to obtain, a common phrase became: "I found it on a Taisai". It's because of this joke that the NM is called Taisaijin.

"From" is usually "から(kara)"　or "より"(yori) in Japanese, and the actual phrase used in the running joke is "峠のTaisaiが○○を落とした" or translated literally "Taisai of Ranguemont Pass dropped it.".

"Taisaijin" is actually "太歳神" in Japanese, which literally translates to "The diety Taisai". Here is some reference from FF11用語辞典, a Japanese version of ffxi wiki.

Taisaijin drops a Scroll of Refresh and Spelunker's Hat, a piece of equipment called the "Anti-Optical Hat" due to it having completely opposite stats to the Optical Hat, which also drops from a Hecteyes mob. Square-Enix added the Refresh drop as irony, where, if players do not kill Taisai for a long enough time, Taisaijin, a mob which does actually drop the scroll, will appear. Spelunker's Hat was likely added as a nod to the fact that people were farming Taisai, which had no useful item, meaning Taisaijin has nothing a player would want (besides as a trophy item, though the title itself, Bye-Bye, Taisai, can be considered a trophy).