After the fall of the Roman Empire, elephants virtually disappeared from Western Europe.
Since there was no real knowledge of how this animal actually looked, illustrators had to rely on oral and written transmissions to morphologically reconstruct the elephant, thus reinventing an actual existing creature. This tree diagram traces the evolution of the elephant depiction throughout the middle ages up to the age of enlightenment.
Some of these are great, e.g. this from around 1400: