I was watching this video and i noticed some scribble like things that controls the bones like IK what is it? video: https://www.youtube.com/watch?v=NkJPfGEcrrA
I believe what you are calling 'scribbles' are the 'custom bone shapes'. Instead of animating the actual bones of the armature, which can be fiddly, it can sometimes be easier to add a custom shape which represents the bone.
These might be shaped to represent the feature of the armature that they control; a bone that controls an eyebrow might be replaced with a custom bone shape that is in the shape of an eyebrow, for example.
Custom bones can be set in the display panel of the 'Bone' tab in the 'Properties' area:
When a mesh is selected as the custom bone shape, the bone it represents will be hidden. The custom bone shape can then be moved or rotated in the same way the original bone could have been.