The word "baka" (馬鹿) is written with the kanji "horse" (馬) and "deer" (鹿), presumably because "can't tell a horse and a deer apart". This is a baka dressed as a deer on a year of the horse.
The word "baka" (馬鹿) is written with the kanji "horse" (馬) and "deer" (鹿), presumably because "can't tell a horse and a deer apart". This is a baka dressed as a deer on a year of the horse.
The guy who tried to pass off a deer as a horse (and got away with it).
Though popular folk etymology aside, the more accepted origin for horse-deer = baka these days is that it's a phonetic transcription from Sanskrit and the choice of kanji aside from their sounds just happened to be coincidence.