Is amoeba an irregular shape?

Complete Answer:

The characteristic of amoeba is the presence of false feet known as pseudopodia which are formed by the bulging out of cytoplasm by the coordinated movement of actin microfilaments. ... But due to the continuously bulging out cytoplasm, pseudopodia results in the irregular shape of the amoeba.

Why are amoebas different shapes?

An amoeba has no shape. It uses its pseudopod (makeshift-foot) to assist with its movement, by extending it out to the desired direction, then letting its body settle in it. While a paramecium has more of an oval-shape and uses cilia (tiny hairs) to help with movement.