How can I attach/constrain objects to a character?

I Want to attach an object to the rigged body mesh so it stays on the same spot away from the mesh, while I need it to still be able to animate. I’ll try to explain with an example: You need a closeup shot on the character while two little soldiers are fighting on it’s shoulder while the guy is running. So his shoulder becomes the battlefield for the soldiers fighting on there.
I hope you understand what I need.

I would really appreciate if someone told me how!
Thanks!

Try adding a “child of” constraint to the object that needs to follow the other object, and setting the target object of the constraint as the object that the constrained object is supposed to follow. So, in the example of the soldiers on the guy’s shoulder, put a “child of” constraint onto the soldier’s armature, and set the target as the big guy’s shoulder bone.
So, I’m not 100% sure this would work for a complex rig, but I did a little test on a cube that moved around, and I made a small cube do some random rotations and location changes, and the small cube stayed on the big cube the entire time while still doing its own movements.

EDIT:

disregard