https://forum.square-enix.com/ffxiv/...s-Tail-vs-Wind
Lynx of Eternal Darkness Tail vs Wind
Date & Time: Any
Frequency: Always
World name: Any
Character name: Lynx of Eternal Darkness
Retainer name: Any
NPC name: Lynx of Eternal Darkness
Monster name: Lynx of Eternal Darkness
Class/Level: 90
Party or solo: Either
In-game time: Any
Area and coordinates: Idyllshire ( 6.9 , 5.7 )
Steps:
Teleport to The Crystarium ( 11.0 , 11.4 ) and talk to the Skywatcher.
Or, teleport Ul'dah - Steps of Nald ( 8.9 , 9.0 ) and talk to the Skywatcher.
Or, elsewhere.
Go to a zone with a "Showers" zone weather effect. "Snow" in Eureka might work too, but not in Pyros,
2. Summon Lynx of Eternal Darkness
Find an indoor place, or compare the tail to a zone with clear skys, that doesn't have the zone weather effect by an outdoor place which does have the zone weather effect.
3. Watch tail twitch erratically outside
4. Go inside, watch tail animate normally

https://imgur.com/ryaD9jr