bad penny, always turns up (comes back) like a

turn up like a bad penny

To appear or return regularly, especially of a person or thing that is unwelcome or objectionable. I'm sure we haven't seen the last of your conniving cousin—he always manages to turn up like a bad penny.
See also: bad, like, penny, turn, up
Farlex Dictionary of Idioms.

bad penny, always turns up (comes back) like a

The unwanted or worthless object or person is sure to return. A proverb in several languages besides English, this expression dates from the days when coins had intrinsic worth and a bad penny (or shilling or crown) was one that was made of inferior metal or contained less metal than it should.
See also: always, bad, like, turn, up
The Dictionary of Clichés by Christine Ammer
See also:
  • turn up like a bad penny
  • a bad penny always turns up
  • bad penny always turns up
  • not darken (one's) door again
  • not/never darken somebody's door again
  • never darken someone's door
  • never darken (one's) door again
  • never darken (one's) doorstep again
  • never darken (one's) doorway again
  • expurgate (something) from (something)