There are two kinds of lizard civilizations in Tibia. On the one hand, you've got the Lizards inhabiting the jungles of Tiquanda. They built a magnicifcent city, but it was overrun by the more barbaric Apes. They are now building a new settlement in Chor. On the other hand there is the lizard civilization of Zao. They are an advanced culture, and strong fighters. It is still unknown if the two civilizations consist of one race, if they're relatives or totally different from each other.
It must also be noted that the Draken live on Zao. They are a breed between Lizards and Dragons and combine the power of both races.