The lizardman fangs are a very common drop from lizardmen. You can use them on Xeric's Talisman to charge the talisman. For every lizardman fang, you will get a teleport charge that will enable you to teleport to any place the talisman can teleport to. The lizardman fang is a tradable item, so if you do not need them, you can also sell them on the GE for coins. They are worth around 20 GP each.