The cuckoo, woodpecker, frogs and owl behind the card game Spore & Skog are made as they call, by 574 lines of Rust, with no recordings. The page runs that same code as WebAssembly: drag the rain, fog and call-rate sliders to shift each creature’s odds of speaking, or press one for a fresh call that is never quite the same twice. Headphones help; the calls are placed left and right.