Whatever I do in Pose Mode of my Rig, Tail of the Rig goes crazy My first rigged object so I will try best to describe. I was trying to rig the horse, first had problem with automatic weights ( as I tried to parent horse object to rig, and finally did it with the Add-on).
Now, Problem is, whichever bone I move, tail goes whirling crazy, also can't put it in rest position, it doesn't allow. Scale is not applied because if I do it, my rig moves and messes up the object it is parented to. Whichever Bone I move, tail starts whirling. Maybe some problem with parenting or IK constraints. I will upload Blender file so if you can try to see the problem. Thanks
There is a Parenting loop.
What is happening is the green bone at the very top of your tail is copying the rotation of a bone that is parented to it (I cannot find it for some reason) this bone is called tail control. When your tail bone rotates, it rotates the control bone, which rotates the parent bone, which rotates the control bone, and so on.
What fixes the problem is simply remove the bone constraint from the green bone. If you still want to keep the copy rotation, just add a bone into your scene, press alt+p to remove parent, and use the new bone you created.