In Hittite Mythology, Illuyankas was a dragon slain by Teshub. There are two versions of this myth.

In the old version, the two gods fight and Illuyankas wins. Teshub then goes to Inaras for advice, and she devises a trap for the dragon. She goes to him with large quantities of liquor, and entices him to drink his fill. Once drunk, the dragon is bound, and Teshub appears with the other gods and kills him.

In the later version, the two gods fight and Teshub, again, loses. Illuyankas then takes Teshub's eyes and heart. Teshub then has a son, Sarruma, who grows and marries Illuyankas' daughter. Teshub tells his son to ask for his eyes and heart as a wedding gift, and he does so. His eyes and heart restored, Teshub goes to face Illuyankas once more. At the point of vanquishing the dragon, Sarruma finds out about the battle and realizes that he had been used for this purpose. He demands that his father take him along with Illuyankas, and so Teshub kills them both.

Source: History of the Ancient Hittites: Hittite Gods