Hi, I am trying to make a simple Milk box Character like this one which I want to be able to do lip syncing on.

I made the following and added a couple of bones and weight painted each one individually



When I try to rotate the bone in Pose Mode, I see severe Mesh Deformation.

I tried to mimic the rig of Melvin by adding several bones around the mouth and weight painted them individually (again mimicking the weight paint on Melvin), but I still have the same issues. Any ideas on how I can fix this?

Thank you.