I fear I may have given too much of the game away with this art.
This is Goosebumps #26: My Hairiest Adventure
Larry Boyd and his friends find a bottle of expired tanning oil in trash (*cough* red herring*cough*). After using it, hair grows all over Larry's body. He shaves it off only for the hair to grow back the next day. Also he has a physician with the unfortunate last name of Murkin. Soon Larry's friends begin to disappear one by one. Throw in two plot twists--one involving Larry's pet cat Jasper and you have this book.
©Scholastic/ RL Stine