bad penny
From Longman Dictionary of Contemporary Englishbad pennybad pennyBritish EnglishDIFFICULT someone or something that causes trouble and is difficult to avoid Sure enough, Steve turned up like the proverbial bad penny (=suddenly appeared). → badExamples from the Corpusbad penny• I took long breaks away from training and would then reappear like the proverbial bad penny, as if I had never been away.