Arnold himself uses "weirdo and funny" to describe himself, particularly because he was born with a condition that means that his brain is "drowning in grease" (Alexie, 2). Especially physically, Arnold is awkward. He has thick black plastic glasses that are handed out for free from the Indian Health Service (Alexie, 3), and he says that his hands and feet are so large that "with my big feet and pencil body, I looked like a capital L walking down the road" (Alexie, 3). He also has a giant head and suffers from seizures (Alexie, 3).
Arnold is also shy and quiet. He tells the reader "every kid wants to go outside. But it's safer to stay at home. So I mostly hang out alone in my bedroom and read books and draw cartoons" (Alexie, 4). He then explains that he draws cartoons as a way to communicate with the world and get the attention that he wants but doesn't know how to ask for otherwise (Alexie, 5-6).
However, Arnold is also determined and brave when he needs to be. He decides to go to Reardan, even though he knows that he will be the only Indian kid and be leaving everyone he knows, in addition to his tribe and his best friend looking at him as a traitor. Additionally, when he is bullied by someone at school making a racist joke on his first day, Arnold immediately punches the bully to end the problem.