What creature/monster types would you use against a party of 3-4 adventurers (within the bracket of 4th-6th level-ish), who had to defend a farmhouse against waves of attackers and any advice of how you would run it?
The farmhouse is by a small river with a waterwheel connected and there is a bridge that goes across to the house. There are open fields and a forest where the majority of the attacks are coming from and I envisage a monster Special Forces attack from the river or bridge at some point during the night.
yep, Bullywugs climbing the waterwheel was exactly the image I envisioned, plus Bullywugs are a great but underutilised creature so PC dont expect them to leap into battleMy default was going to be undead but ooh Bullywugs! I can see them stealth-swimming and using the waterwheel to get to the roof while the diversion of the giant toads or whatever try to attack from the front.
Blights led by an evil druid.Blights are very plant-y and forest-y, and can cause an extra problem if they can turn the crops into more blights.