What is the figure of Judaism?
It depends on how the word "figure" is read.
If it is referring to which human being is the most important historical personage in Judaism, that would be the Prophet Moses, who received the Torah and helped the Jews escape bondage in Egypt.
If it is referring to which symbols represent Judaism, those would be the Star of David and the Menorah (or candelabra).
The menorah is the religious symbol of Judaism.