Malerve is a weed found in the Tutorial Village. The NPC woman says that the Fiendi are attacking the village, and they just ran out of malerve.
Malerve is useful for taming the wild Fiendi. Using it is one of the ways to complete a quest.
Malerve in the ComicEdit
Kat picked some malerve to finish a small part of the Alignment Tutorial. She made it into a lasso and captured the Fiendi just before it could attack the NPC woman.