allah has created every moving creature from water. of them there are some that creep on their bellies and some that walk on two legs and some that walk on four. allah creates what he wills. verily allah is able to do all things.
والله خلق كل دابة من ماء فمنهم من يمشي على بطنه ومنهم من يمشي على رجلين ومنهم من يمشي على أربع يخلق الله ما يشاء إن الله على كل شيء قدير