Moonstone Locust

From Xiaolin Showdown Wiki

The Moonstone Locust is a Shen Gong Wu, noted for being the only thing that can defeat the Heylin Plant. Although this is its only specifically mentioned use, it has been seen in the last episode's showdown that it might be able to devour any type of plant it is directed at.

[edit] Abilities

The Moonstone Locust releases white, stone locust insects that will devour The Heylin plant (or any plant according to later episodes.)