Lions were apparently of symbolic importance to the Hittite civilization, and images of them can be found at many Hittite sites (and indeed throughout the near east), including the Hittite sites of Aleppo, Carchemish and Tell Atchana. The image most often associated with Hittites is the sphinx, combining a lion's body with an eagle's wings and a human head and chest.
Peter Neve. 2000. "The Great Temple in Boghazkoy-Hattusa." Pp. 77-97 in Across the Anatolian Plateau: Readings in the Archaeology of Ancient Turkey. Edited by David C. Hopkins. American School of Oriental Research, Boston.