Negev Beasts.
The Palmach, an elite force of the Haganah (Jewish Paramilitary organisation, later would become the core of the actual IDF), by the War of Independence, 1948/49, the Palmach was expanded to three infantry brigades, iirc these were the Negev, Yiftach and Harel.
The Palmach was disbanded in 1948 when the IDF was created. Still, the Palmach officers were the backbone of the IDF in the following years after 1948.