This madcap chapter book series from Hay (There’s a Sea Witch in My Swim Class) and Oliveira (Fern and Newt and the Lost Loot) gets off to a splashy start as a group of amateur elementary school detectives embark on their inaugural investigation into monster tomfoolery. On the first day of the new school year at Baffling Elementary, an overflowing bathroom has Principal Dangle on edge. While the principal believes that a plumbing problem might be the cause, friends and students Lucas, Mia, and Noah aren’t convinced. Following a trail of watery footprints to the library, the trio, portrayed with various skin tones, discover the real culprit: a cat-size, anthropomorphic blue sponge with a toothy grin and pointy claws, which they find devouring a book beneath a beanbag chair. Though the creature disappears in the chaos following its discovery, fresh footprints in the bathroom prove that the children’s mark is still at large, prompting Mia to rally the boys and set a trap. Grayscale illustrations with electric blue accents inject the protagonists’ amiable, low-conflict adventure with visual humor, while bouncy text emphasizes observation, persistence, and teamwork. It’s delightfully absurd. Publishing simultaneously: The Tentacled Terror. Ages 5–9. (Jan.)–Publishers Weekly