(FYI This book is for advanced origami enthusiasts, aka teenagers and adults!)
Origami Animal Sculpture, by John Szinger is a wonderful advanced origami book for ones who want to create lifelike and expressive origami models inspired by nature. Individuals who are detail oriented and able to stick with a long instruction sequence will find the results extremely rewarding as you’ll have the opportunity to practice patience and teens will have a leg up when they take geometry. The nerds in geometry class will have fun calculating all the angles and fully comprehend the mathematical principles it would take to create these models.
My favorite ones are the octopus and turtle.