Boris is Joe's stuffed duck doll. Boris is probably a handmade duck, considering his beanbag like appearance and buttons for eyes. He was made by Joe, but in Blue's First Holiday on the day we met Blue, he is right next to him as a baby. This means either the story about Joe having made Boris was retconned or he appeared with baby Joe as a matter of artistic license on the writers' part.
Boris is mostly golden yellow. He has an orange beak and orange feet. Boris has a pair of mismatched black buttons for eyes. He was handmade.