Ok so I get asked A LOT on my pics "Why does Ron have scars on his arms?" So instead of explaining it every time, I'll just explain it here and link them to this.
"In the Battle of the Department of Mysteries, Dumbledore's Army and the Death Eaters fought in a room in the Department of Mysteries with a tank full of brains known as the Brain Room. A Confunded Ron Weasley thought the brains were funny and summoned them. After the thoughts soared at him, they started to wrap themselves around Ron's arms, nearly suffocating him. When the battle ended, Madam Pomfrey said that it would leave a scar since nothing leaves deeper scarring than thought