Just Blender and Unity. I model/sculpt the monsters, give them an armature, import the .blend file into Unity, use a Ragdollifier.cs script to create an approximate ragdoll from CapsuleColliders and ConfigurableJoints (or CharacterJoints) and then manually adjust that approximate ragdoll to fit the model better. Then I animate it by applying forces to different parts, like you would a puppet. The simplest example is to apply an up-force to the head, and down force to the feet to make it stand upright. Then alternating up and down forces to the feet to make it step around randomly.
There are some scripts and an explanation here: https://github.com/Jackson-Rain/UnityScripts
Although they are currently a little outdated.