Sonic's appearance varies greatly depending on the medium and the style in which he is drawn. In the video games, Sonic's original design by Oshima was short and round, with short quills, a round body, and no visible irises. Artwork featuring this design and drawn by Akira Watanabe was displayed on the package artwork for "Sonic the Hedgehog". Sonic's proportions would change for the release of "Sonic the Hedgehog 2" on the Mega Drive; Sonic's head to height ratio was changed from 1:2 to 1:2.5. For the 1998 release of "Sonic Adventure", Sonic was redesigned by Yuji Uekawa as a character with longer legs and a less spherical body, longer and more drooping quills, and green-colored irises. For the 2006 game, Sonic was redesigned to make him look adult-like and taller to appeal to the next generation players. This was also done because Sonic would interact with humans more often and his design was supposed to fit. An alternative "Werehog" form was introduced in "Sonic Unleashed", placing more emphasis on Sonic's melee skills rather than speed. Although Tetsu Katano acknowledged the large negative fan response to the Werehog, he believes it could return in a future game.