We Disagree About This Tree by Ross Collins

Bear and Mouse have finally overcome their differences and are living together in perfect harmony … until it’s time to decorate the Christmas tree! Bear wants dazzling lights, while Mouse prefers gigantic baubles … and, wait a minute, did Mouse just put a MANATEE on the top?! A topsy-turvy tree is definitely THE LAST STRAW and it looks as if Christmas is RUINED. But maybe, just maybe, Bear and Mouse can reach a compromise in time … ? -Goodreads