What the achievement asks
Photograph seven legendary characters while running the cataloguing world quests. Ten points, account-wide.
They do not appear until you unlock them
Legendary characters only start showing up once you have taken the Lucky Rock talent in the Expedition Supplies tree, which Pathfinder Jeb opens at 47.2 83.4 in The Waking Shores.
Without it you can ride every cataloguing quest in the expansion and never see one, and nothing in the game connects the two. Take Lucky Rock first, then start looking. The whole tree is Well Supplied in the same branch, so it is work you owe anyway.
The seven, and which ride each one is on
| Character | Cataloguing quest | Where along the route |
|---|---|---|
| Abu'Gar | Cataloging the Waking Shores | By the Life Vault Ruins flight path |
| Chen Stormstout | Cataloging the Waking Shores | East of Obsidian Bulwark |
| Elder Clearwater | Cataloging the Ohn'ahran Plains | By Forkriver Crossing |
| Nat Pagle | Cataloging the Ohn'ahran Plains | Central Ohn'ahran Plains |
| Chief Telemancer Oculeth | Cataloging the Azure Span | East of the Azure Archives |
| Time-Warped Mysterious Fisher | Cataloging Thaldraszus | South of Valdrakken |
| Wrathion | Cataloging Thaldraszus | By Algeth'era |
Four cataloguing quests, seven characters, and only the quests that happen to be active this rotation are available to you.
Two layers of randomness, and the trick that removes one
Which cataloguing world quests are up changes with the world quest rotation, which turns over twice a week: Tuesday and Friday mornings in the Americas, Wednesday morning and Saturday evening in Europe. An unlucky rotation can offer no cataloguing quest at all.
On top of that, the legendary character is not guaranteed to spawn on a given run of a quest that is up.
The second layer is the one you can beat. Quest progress does not register while you are in a raid group, so the world quest never completes and you can ride the same route again and again until the character you need turns up.
Convert to a raid before your first photograph, not after. If you complete the quest by accident, that route is gone until the next rotation, and a missing character can cost you half a week.
The same protection comes from simply not taking photographs on a run where the character is absent, or from abandoning the quest before it completes, but the raid group is the version that lets you shoot freely.
Photograph everything while you are riding
Every shot you take on these rides also counts towards Great Shots Galore!, which wants a hundred of them and uses the identical raid-group trick. Riding for one and ignoring the other is throwing away the expensive part, which is the rotation, not the ride.
Where it fits
One of eight under Wake Me Up, which rewards a Bestowed Ohuna Spotter and is a piece of A World Awoken.