|"It'll be fine. Every cat knows that Emberstar's closest friend is Thistletail, in ThunderClan. If any cat understands that friendships don't stop at the border of a territory, it's Emberstar."|
|— Ryewhisker in Code of the Clans, page 12|
|Living:||Code of the Clans|
Thistletail is a cat with an unknown description and gender.
In the Field Guide Arc
- Thistletail does not formally appear, but is mentioned by Ryewhisker telling his mate, Cloudberry, as being Emberstar's best friend, even though Emberstar is the RiverClan leader, stating that friendships don't stop at a border.