He's now bald. (After the tumor operation, it was just a portion of his hair that was shaved)
The doctors needed to put a shunt in his head. That's a tube that runs from the side of his head to his peritoneal cavity. He was having seizures when the space that the tumor took was being filled with liquid. That creates pressure on his brain which causes his seizure. This shunt aims to help him drain that fluid out. This is a permanently affixed to his head now.
They also did tracheostomy and gastrostomy on him. It's because the tumor's location is very close to the brain stem. That means that it may have affected that area too and that controls bodily functions such as breathing and swallowing. So to aid in his recovery, the tracheostomy will help him breathe. On his own, he takes 1 to 2 breaths only. Gastostomy is the process of putting a feeding tube directly to his atomach.