Houdai
From Starfy Wiki
"Battery" redirects here. For the Treasure Item in Densetsu no Starfy 2, see Treasure Items#Densetsu no Starfy 2.
Houdai (Japanese: 砲台, literally meaning 'artillery battery') are red circles marked with the letter 'Y' inside them, with a red arrow pointing in a certain direction. They only appear in The Legendary Starfy. They are found in Hotcha Springs, Glitzem Grotto, S.S. Logwater, Planet Bunnera, Pufftop and the ??? Stage.
If the Y button is pressed while Starfy or Starly is inside a Houdai, they will be stuck inside it and stars will appear out of it. If the player presses the Y button again or waits for a while, it will fire Starfy or Starly out of it in the direction that arrow is facing. Some Houdai can move.