Island of the Blue Dolphins

From the text:

I watched him stride off to get the spear, a little boy with thin arms and legs like sticks, wearing a big string of sea-elephant teeth. Now that he had become Chief of Ghalas-at, I would have even more trouble with him, but I wanted to run after him
and take him in my arms.

Ramo made himself chief. He dressed like a chief, tried to act like a chief, and even gave himself a new name...... Chief of Ghalas-at.