chameleon

Concise Oxford English Dictionary © 2008 Oxford University Press:
chameleon /kəˈmiːlɪən/ (also chamaeleon)

▶noun a small slow-moving lizard with a prehensile tail, long extensible tongue, protruding eyes, and the ability to change colour. [Chamaeleo and other genera, family Chamaeleonidae: numerous species.]

– derivatives
chameleonic adjective.

– origin ME: via L. chamaeleon from Gk khamaileōn, from khamai ‘on the ground’ + leōn ‘lion’.