Happy Birthday! is the forty-third episode of the Annoying Orange series. This episode features Orange's birthday party in which his friends attend.
Midget Apple is hiding in Orange's cupcake. Orange is having his first birthday, but he arrives late for the party. Pear and Lime wait with Midget Apple in a cupcake so that he can jump out and sing to Orange. Marshmallow arrives, and immediately tries to become Midget Apple's friend, which Midget Apple somewhat agrees to. Orange arrives, and the party begins. First he does target practice with seeds (bursts one balloon that makes Pear inhale helium and his voice gets squeaky and similar to the one of Midget Apple), chats with the gang, and gets a birthday present: a "Wee Pony" (when he actually wanted a Wii Pony) who starts to eat Marshmallow. However, after the candle melts on the cupcake and starts it on fire, the frosting is blown onto Marshmallow's head, who is kicked into Lime. Soon, Knife comes to wish Orange a happy birthday, but kills Lime, and Marshmallow is eaten a little more by Wee Pony. The episode ends with Midget Apple asking if it's okay if he can get out of the cupcake.