Insects with parasitic plants...... Although it's a form of Cordyceps, it differs from what modern day humans know. These insects have grown to gigantic sizes that betray them being insects. People who don't like insects might completely lose their minds when encountering these beasts. Moreover, they are capable of "living and moving around" with the plants attached.
Most of the Plasect are carnivorous, and with an ability to easily mimic the look of plants, they chiefly prey on the Hourai and Lycanthrope. Since Plasect are used to make goods like honey and sap, they are generally seen as beneficial to all humans in the Green World, they aren't considered pests, and people don't push for a mass extermination. By the way, the Plasect ultimately are a nursery for the Cordyceps, so they tend to be used as part of an antibiotic used by the Hourai to stave off their transformation into plants.