A Unity ID allows you to buy and/or subscribe to Unity products and services, shop in the Asset Store and participate in the Unity community.
Separate names with a comma.
For anyone else: I stumbled on this page while looking for humanoid + avatar mask problems. Didn't find my solution here but elsewhere. In the end...
Meanwhile, September 2016, Unity 5.4.1f1 I guess we're all still waiting for that zoom option in the animator.