slowcoach
noun [ C ] UK informal uk/ˈsləʊ.kəʊtʃ/ us/ˈsloʊ.koʊtʃ/ (US slowpoke)
动作迟缓的人（尤指儿童）
someone, especially a child, who is walking or doing something too slowly
[ as form of address ] Come on, slowcoach, we don't have all day you know! 快点儿，磨磨蹭蹭的家伙，要知道我们可没有一整天的时间！