Teumessian fox

In Greek mythology, the Teumessian fox was an enormous fox that was destined never to be caught.

Mythology
It was said that the Teumessian fox had been sent by the gods (perhaps Dionysus) to prey upon the children of Thebes as a punishment for a national crime. Creon, then-Regent of Thebes, set Amphitryon the impossible task of destroying this beast. He discovered a supposedly perfect solution by using the magical dog Laelaps, who was destined to catch everything it chased, to catch the Teumessian fox. Zeus, faced with an inevitable contradiction due to the paradoxical nature of their mutually excluding abilities, turned the two beasts into stone. The pair were cast into the stars and remain as Canis Major (Laelaps) and Canis Minor (Teumessian Fox).

Naming
In reference to Cadmus, the legendary founder of Thebes, the Teumessian fox is referred to by the elegant variation Cadmean vixen in James George Frazer's 1921 translation of Bibliotheca (Pseudo-Apollodorus), though in the Greek texts the sex of the fox was not specified. The terms Cadmeian vixen and Teumessian vixen are used by the Oxford Classical Dictionary (1948) and The New Encyclopædia Britannica (1985).