Heavily inspired by The Sims 4's possessed mood in Strangerville: This was actually drawn due to a fear of that specific mood in the game.

Possession in my universe happens by touching The Queen Deceiver's (Ruler of a plant-based monster kingdom that feeds off of the life of others)
If it isn't treated they will begin to exhibit strange behaviors involving planting more of these mysterious fruits and talking incredibly fast, turning their head in all directions along with unnatural limb contortion, random maniacal laughter, wandering around, and more.

The infected still have a chance to snap out of this strange trance-like state. If multiple days pass then they will fully transform into a mindless possessed body, incapable of remembering who they really are and returning to their normal state. After the transformation is complete it's impossible to bring them back. The only thing you can do now is kill them off to prevent the infection from spreading.