Tarasque or Tarasconus was a sort of great evil dragonish-(or bat)-beast-fish Hybreed. Its appearance was described like this:
It had a Lion's head, a serpent's tail, two bat wings (versions differ, saying it was onlye two sings and other that it had two on either side), and its body was that of a scally fish. It was often shown with six lion legs, and the paw of each leg had long and sharp claws. It was supposed to be greater than an ox and longer than a horse, so two meters wide, two and a half tall, and maybe three or four of length would be a good estimate with such crude mesurements.

It was also said to be as strong as 12 lions (or bears, depends on the version of the story), with teeth as sharp as spear heads (or swords), and that it had a taste for human flesh, and that it had the ability to defecate firey ordure for (as it said in the stories) "...The space of an acre of Land".

The monster was conquered by St. Martha, as it appears in the stories of "The Golden Legend" by Jacobus de Voragine's, basically she went into the beast's forest, which was between Arles and Avignton, (the beasts habitat was around the river Rhone, near Tarasin in France) and into its cave. There, she cast holy water on it and showed it the holy cross, and at this the creature "was overcome and stood still" (this is because it was born from the evil sea serpent Leviathan and Bonnacon. The real problem being the sea serpent, because it was trully 100% evil. So to put it simply, the Tarasque has demonic origin and thus the holy water and holy cross petrified it with holy power). The she blinded the beast with her gridle, and told the news to the people of the town that the beast had being terrorising. When they heard this news, the people of the town rushed to its den with spears and swords and knifes and cuted it down.

Then a church was built in Honor of Martha, who stayed in the woods of the beast and lived there. The church was built on and around her burial place. By the time she died, the town (the name of the town is Tarascon) had grown up around it. The towwn is till holds parades on the las Sunday of June each year in remembrance of this event.