Boost Ball

From Wikitroid, the Metroid wiki

Boost Ball is an upgrade to Samus Aran's Morph Ball. While in Morph Ball Mode, Samus can press the jump button to "boost", or speed up for a short period of time. It is essential in getting a Dark Torvus Temple Key, beating the Spider Guardian, and shutting down Quad MBs and Dark Quad MBs.

It is seen in Metroid Prime, Metroid Prime: Hunters, Metroid Prime 2: Echoes and Metroid Prime 3: Corruption. It is the only item that allows Samus to traverse large halfpipes. It can also be used to destroy small enemies or damage larger ones with the boost. It is acquired in Prime by going to the Phendrana Canyon in Phendrana Drifts, after killing the Boost Guardian in Echoes and after fighting the Defense Drone in Corruption. In Hunters, Samus begins the game with it.

Morph Ball
Morph ball | Bombs | Power Bombs Spring Ball | Boost Ball | Spider Ball Hyper Ball