The troll's toe cheese

"Fart, Pan, Moxie, and TickTock are facing their scariest challenge yet--an angry mom! The Great and Powerful Kevin has promised Pan, who lost her mother when she was a baby, that she could see her mom one last time. But instead, she sees a distorted spirit of her mother, transformed into an evil creature bent on revenge against those who caused her death. Meanwhile, some new information comes to light, and Fart and friends head out on a rescue mission. Deep within the goblin caves, they search for evidence of their long lost masters, facing goblins, fire rats, floor fiends, and a troll with some seriously disgusting toenails along the way"--