Pufftop Proof
From Starfy Wiki
The Pufftop Proof (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 Starfy 5, but is expressly called the "Pufftop Proof" in the Japanese version of the game. When Moe asks Starly how she knew where they were in the 4th stage of Gluglug Lagoon, Starly says that members of the Pufftop Royal Family (テンカイいちぞく/ Tenkai Ichizoku, lit. Pufftop Family) have a symbol that connects them, and that she has one that connects her to her brother.
Starly also gives one to Moe so that Starfy can call her for help if they need it.