画虎类犬 — “Draw a tiger, resemble a dog”

The idiom "画虎类犬" (Huà hǔ lèi quǎn), meaning "to draw a tiger but end up with a dog," originates from a story about Ma Yuan, a renowned general of the Eastern Han Dynasty, also known as General Fubo.

Ma Yuan had two nephews, Ma Yan and Ma Dun, who were fond of gossiping about others. Worried about their conduct, Ma Yuan wrote them a letter. In it, he expressed his lifelong aversion to discussing others' faults and advised them to listen to such discussions as if they were about their own parents—merely listen, but never participate.

He then suggested they learn from Long Bogao, a kind, cautious, frugal, and humble man whom Ma Yuan greatly respected despite his modest position. Ma Yuan urged his nephews to emulate Long Bogao.

Conversely, he mentioned Du Jiliang, a chivalrous and righteous individual who shared joys and sorrows with people of all kinds. While Ma Yuan respected Du Jiliang, he did not wish for his nephews to follow his example.

Ma Yuan explained his reasoning: "If you try to learn from Long Bogao, even if you don't fully succeed, you can still become a cautious person, much like attempting to carve a swan but still managing to create a duck (刻鹄类鹜). However, if you try to learn from Du Jiliang and fail, you will become a frivolous and unruly person. This is like trying to draw a tiger but failing so badly that it resembles a dog (画虎类犬)."

This anecdote warns against blindly imitating a challenging or complex model without sufficient skill, which can lead to a clumsy and undesirable outcome.