 The opening credits of each episode has a different sound effect relating  to the episode as the "2020" turns to "2021":  In the episode "Radio Free" the sound effect is radio static.  In the episode "Happy Cake" the sound effect is an electronic door  opening.  In the episode "I, Robot" the sound effect is a pneumatic drill.  In the episode "Chickmate" the sound effect is a baby crying.  In the episode "Predator" the sound effect is a monster growling.  In the episode "Lost in Time" the sound effect is a zap.  In the episode "Little Orphan Angry" the sound effect is a child  coughing.  In the episode "Waking Quinn" the sound effect is a zap.  In the episode "All That Jazz" the sound effect is a gurgle.  In the episode "Murphy Murph and the Feng Shui Bunch" the sound effect is  a gong.