pig's ear

a pig's ear (mess, ) — ...

make a (real / right) pig's ear of sth/doing sth{UK} (do something very badly; make a complete mess of sth) — ...

Example 1: You've made a right pig's ear of this. Let me do it!
Example 2: ...

see also
[dog's breakfast]
[кое как]
[черт ногу сломит]