They show up infrequently in Missionary Forest and more frequently in the Training Fields (which are unlocked after the Lotus Trial is completed).
¿Prueba del Loto? Y eso como lo desbloqueo.
The trial is closed until after you've spoken to Malcolm. He's in the historical society building (the bigger one on the north side of town, second floor). He's supposed to help you get information about Missionary Cave.