Lakitus are Koopas who employ clouds as vehicles. However, Lakitus themselves have a rather different appearance than the normal Koopa Troopas; Lakitus have very different heads with much smaller, circular noses, all generic Lakitus wear thick goggles, and Lakitus have a ring pattern on their shells rather than the hexagon pattern featured on those of Koopas. Also, while most Koopas (other than the Dry Bones of certain Paper Mario games) have no hair at all, Lakitus are usually depicted with three small strands of hair, or (as seen in Mario Superstar Baseball) a small clump of black hair.
However, Lakitus are most differentiatable from Koopa Troopas in that they simply ride clouds. These clouds have changed over the years perhaps even more than Lakitus themselves; although 8-bit Nintendo Entertainment System games depicted Lakitu as riding a cloud identical to certain block-like cloud platforms (except with a green outline rather than black due to graphical limitations), Super Mario World (which still included these small platforms of old) gave Lakitus more realistic, larger clouds to commandeer.