My headcanon for Terrako is that the reason why it's apparently unique is that Young Zelda just put a bunch of pieces together in a way that fit, but weren't meant to go together. I figure the little fella shouldn't actually function, but Zelda's pure heart and magic power gave it life.

a cartoon character with a blue eye is walking on a brick path

Alt: Terrako, a small white robot with a blue going eye, looks around briefly before startling and lifting the small slide whistle apparatus on top of it.