Neutrophils and monocytes can move about like amoebas. This kind of movement uses pseudopodia (false feet).
All the white blood cells are able to move like an amoeba, and can migrate out of blood vessels into the surrounding tissues.
Amoeboid movement is a crawling-like type of movement in which the cell forms temporary cytoplasmic projections called pseudopodia towards the front of the cell.
This type of movement is observed in amoebae (e.g. Amoeba proteus). Their cytoplasm consists of plasmasol (central fluid) surrounded by a more viscous plasmagel. The plasmagel is converted to plasmasol causing the cytoplasm to slide and form a pseudopodium in front to move the cell forward.
Cells that move this way are referred to as amoeboids. Apart from amoeba, other examples are cellular slime moulds (e.g. Dictyostelium discoideum), and human cells, particularly Kupffer cells of liver, macrophages, and cancerous cells.