These drawings are fictional animals designed to live on planets different than earth. It is said by many scientists that more skinny and slim organisms would survive better on planets with a lower gravitational pull. This would support their weight and make it easier for them to move around.
My inspiration came from H.G. Wells' classic novel "War of the Worlds." It is explained in the book that the Martians have bodies similar to that of octopuses because of Mars' very low gravitational pull.