The story behind "马虎 mǎ hu"

It is said that there was a confused painter in ancient times. One day, he just finished drawing the head of a tiger when his friend came by. His friend asked him to draw a horse. The painter was too lazy to start a new one, so he drew a body of a horse right under the tiger head. His friend asked him what he was drawing, a horse or a tiger? The painter said"Oh, it's almost the same."
      After his friend left, the painter hung the painting on the wall. His elder son asked him"What is this ?" The painter told his son it was a horse. Then the next day his little son asked him the same question as his elder son did, and the painter told his little son it was a tiger. So the painter's two boys totally had no idea what was a true horse or a tiger.
      One day, the elder son met a tiger which he thought was a horse, he was trying to ride it, apparently he end up died. The little son met a hard-won horse which he thought was a tiger. He was afraid, so he shot the horse with the bow.
      After those, people gave the painter a nickname"Mr. 马虎(马虎先生mǎ hu xiān sheng).
 
horse 马 mǎ
tiger 虎hǔ/老虎lǎo hǔ
马虎 mǎ hu，careless; slovenly; casual; slack; perfunctory