The CAIMAN

I am trying to make the caiman bite...but it is being a pain manually painting the skull extra bone to move the jaw
 I changed clear weights in avastar plugin from ticked to no ticked and I could paint...just to find out that the skull bone position will never allow me to open the caiman's jaw. I need to switch the skull bone position from the tip of the head bone to its base:

 It was easier than I thought. I only needed to disconnect bone! ...and placing it under the jaw allowed me to operate the mouth movement of the caiman:

using blender addon rigify and the "rigify buttons" spare bones to rig the tail... it is getting really creepy...

decent blender water thanks to this short tut: https://www.youtube.com/watch?v=WdaQ7ee_IXQ

And unreal engine 4 water thanks to this other:  

UnrealEngine4WaterTutorial

result: