Pufftop Proof
From Starfy Wiki
Not to be confused with the Starfy 4 Stuff Item of the same name, the Pufftop Proof (Japanese: テンカイのあかし, Tenkai no Akashi) is the stone that Starly uses to teleport to Starfy in The Legendary Starfy. It goes unnamed in the English version of The Legendary Starfy (fifth game), but is expressly called the "Pufftop Proof" in the Japanese version of the game.
When Moe asks Starly how she knew where he and Starfy were in Gluglug Lagoon Area 4, Starly says that the Pufftop Royal Family (Japanese: テンカイいちぞく, Tenkai Ichizoku, lit. Pufftop Family/People) have a symbol that connects them, and that she has one that connects her to her brother.
Starly gives one to Moe so that Starfy can call her for help if they need it.