画虎类狗

huàhǔ-lèigǒu

(1) [try to draw a tiger and end up with the likeness of a dog-make a poor imitation]∶没有画虎的本领, 结果把虎画成了狗

(2) [attempting more than one has ability for]∶比喻理想太高, 终无所成, 反留下笑柄