Megakaryocytes
Usually the largest cells in the bone marrow that are 10 to 15 times larger than a typical red blood cell. The maturing megakaryocyte grows in size and replicates its DNA without nuclear division resulting in a very large, lobulated, nucleus with many copies of the usual complement of DNA, as much as 64 times most cells. They are multinucleated and responsible for making platelets.
Atlas Link: Megakaryocyte