The Irish giant deer was the biggest deer the world ever seen. This deer was thought to be remained alive during the late Pleistocene and early Holocene age. This strange deer resided in Eurasia from Ireland at the Eastern Baikal Lake. This mysterious deer was very famous for its huge size. This giant deer was about 2.1 meter or 7 feet tall at the shoulder and its approximate weight was 90 pound. But the most astonishing thing was its long branched horns which are called antlers. Its antler were 12 feet from tip to tip. This strange species had been extinct from the Universe before 5700 B.C. Main discussion generally goes on not depending on their huge body but on their large antlers.