One of the first encounters in my "mature" game was an attack by an assassin vine on the poor warlock girl. Flavorwise, I did the assassin vine as having violently twisting and writhing tentacles that would sweep over a victim's body, groping about blinding looking for any opening, hoping to smother the victim. Of course, people have other openings besides their mouth
. They killed it, but it was such a memorable encounter that I decided to make the assassin vine a recurring villian.
You heard me.
Here's what happened: A druid, angered that they have desecrated an "innocent" denizen of the forest (and others with their adventuring shenanigans), she revives the assassin vine and Awakens it. It's now a buggering tree out for VENGEANCE!