画蛇添足

huà shé tiān zú

to spoil something by adding what is not needed

Character by character

画huà
draw

蛇shé
a snake

添tiān
add

足zú
feet

文章到这里已经很完整了，再写就是画蛇添足。

The essay is complete at this point; anything more would be gilding the lily.

Tone: negative (criticism).

In a drawing race the fastest man added feet to his snake and lost the wine.

Learn this in Lesson 108 · HSK 7–9: 怎样把道理讲清楚 (Building an argument)

A dialogue, a reading, word cards with audio and a drill that uses it, in Learn Chinese with Bao. The first lessons of every level are free.