A Legendary appears for a few hours, usually at a big event.
1
Watch for the alert
You’ll see a gold "spotted" chip in Hunt mode and a feed post like "A Kirin was spotted at the State Fair! · 2 h left".
2
Be there
Open the sighting and get directions. You can only try when you’re at the spot.
3
Nom-off and catch
You get 3 tries. A win fills your catch meter; reach the Legendary line (85, lower with snacks) and it’s yours. Short of it, your meter is kept for your next try. Each sighting ends when time runs out or all are caught.
4
Rare raids
HQ also runs Rare raids: a Rare Nomling at an event, with a plain ring instead of a gold one. It works the same way, with the Rare line (65). Rare raid alerts are off until you turn them on, and come at most once a day.