Moving Grass

From Zelda Wiki.org

Moving Grass is a curious growth of grass found only in Majora's Mask which Link will find standing in groups of about nine. The special thing about this grass is that after Link has cut one or more of them, the other ones will start to jump away. After a while it will, quite literally, destroy itself. By wearing the Keaton's Mask when attacking the grass, when it is all destroyed a Keaton will appear.

This special grass can be found only at Milk Road, The Mountain Village and in North Clocktown.

Trivia

• Moving Grass always drops one green Rupee when slashed. However, it drops nothing when it destroys itself. If all Moving Grass is destroyed in a single attack, it will also drop a red Rupee.