Articulated Foldable Sea Turtle

Sea turtles suit a jointed model better than most animals do. The shell stays a fixed, solid anchor while everything around it sweeps and shifts, so a chain of moving segments actually looks like swimming rather than looking like a toy pretending to swim. This one adds a fold to that, closing down into a compact shape or opening out into the stretched-flat glide posture you see in wildlife footage. The carapace carries the plated scute pattern of a real turtle, which is what stops the whole thing reading as a generic flexi animal — it is recognisably a sea turtle and not a tortoise. It lives happily in two places: on a desk as something to fiddle with while thinking, or in a child's hands as a toy that expects to be carried around. It is also one of the better things to hand somebody who has never watched a 3D printer produce something that moves.