slowcoach
From Longman Dictionary of Contemporary Englishslowcoachslow‧coach /ˈsləʊkəʊtʃ $ ˈsloʊkoʊtʃ/ noun [countable] British English informal SLOWsomeone who moves or does things too slowlyExamples from the Corpusslowcoach• Come on, slowcoach! If you don't hurry up, we'll be late.