Monocytes
A type of white blood cell (myeloid lineage). These are usually the largest circulating cells in the blood and usually 2-3 times the size of a mature lymphocyte. Their nucleus is usually folded, and there is a large amount of light blue cytoplasm and commonly show cytoplasmic vacoules. Monocytes that leave the blood and enter tissue are called macrophages.
Atlas Link: Monocyte