Submarine Yoshi

The Yoshi Submarine was a form of Yoshi that could be transformed into in Super Mario World 2: Yoshi's Island by touching a Morph Bubble.

The two tasks it performed were travel through bodies of water (because normal Yoshis could not go any deeper into water than the very top), and shoot homing torpedoes (because Yoshis couldn't attack in special forms).

The Yoshi Submarine reappears in Yoshi's Island DS; however it no longer shoots torpedoes.