In this lesson, you'll finish the bone structure by creating the neck, head, and hair bones.
Create the final bones:
On the Create panel > Systems object type, click Bones to enter creation mode.
In the Bone Parameters rollout > Bone Object group, make sure the Width and Height values are set to 5.0.
In a side viewport, create two smaller neck bones, then one bone for the entire head, and then five more bones for the hair.
Use the Bone Tools dialog to create a color gradient for the bones and add fins as desired.
Rename the bones to the following:

Look at the bone structure:
At this point, all of the basic bone structure for the rig is done. You can now unhide all objects to show all the bones you created.
In this tutorial, you learned to create a bone structure for a fully articulated character.
If you have never rigged a character before, you can do the rigging lessons in the Introduction to Character Rigging tutorial before rigging this character.
To learn to skin this character, see the lesson Applying Skin to the Alien.