Americans have the proverbial: If you like duck-duck-like walk; sound; if you look like a duck, it probably is a duck!

The meaning of this saying is that if you see something that looks like a duck or goose is probably the whale or not and the Zebra is what you think, that is the duck. Of course, there is no guarantee that it must be a duck, for example, someone may have made a mechanical duck to deceive you, or you may not understand the signs of being a duck well and the fault may be due to your senses, but the predominant suspicion is the duck.