In substitution type of questions, some particular objects are assigned code names. Then a question is asked that is to be answered in the code language.
If the animals which can walk are called swimmers, animals who crawl are called flying, those living in water are called snakes and those which fly in the sky are called hunters, then what will a lizard be called ?
Clearly, a lizard crawls and the animals that crawl are called 'flying'.
So, 'lizard' is called 'flying'.