Glide (known in Japan as the Giant Flying Squirrel Jump, ムササビじゃんぷ) is an ability that allows Starfy and Starly to reach much farther places than before. In Densetsu no Starfy, Starfy knows it at the beginning of the game. It is taught by Gaganmo in Densetsu no Starfy 2 and Densetsu no Starfy 3.
It is acquired in the third level of Lobber's Villa in Densetsu no Starfy 4, after Starly requests Starfy to find a Treasure Box (which requires the Glide ability) to prove he is a legendary hero after Mattel is impressed to see the famous hero of Pufftop.
Description from The Legendary Starfy
"Glide through the sky with this floaty maneuver."