Billy'snotliketheotherkids.He'sabitmoody,abitcranky,abit...grumpy.Inhopesofcheeringhimup,hismomtakeshimandhissistertotheanimalrescueoneSaturdaymorning.Alltheanimalsarecuteandplayful,butthey'realittletoohappyforBilly'staste.WhenBillywandersintoanothersectionofthestore,however,hestumblesacrossadifferentgroupofanimalsawaitingadoption.Thesepetsaregrouchyandscruffy.Infact,theyseemdownrightgrumpy—justlikeBilly!Hecatchestheeyeofaparticularlygrumpypup—couldthisbethefriendBillyhasbeenlookingfor?GrumpyPetsshowsthatthere'saperfectmatchforeveryone,ifyoustaytruetoyourself.