The episodes starts with the pigs waking up and getting out of the building they were sleeping in. All the pigs except for one were still sleepy. It appeared that today was his birthday. However, none of the pigs took notice. Once Corporal Pig gathered the pigs to instruct them on something and then dismissing them, the birthday pig went near him, trying to get the leaving crowd's attention in vain. Corporal Pig then went over to him just to stop the annoyance, but the birthday pig blew the party whistle in his snout, enraging him.
Later in the Square Forest, while working, the birthday pig was thinking of a huge birthday cake. This distracted him and as a result, the tree he was sawing fell on him. Corporal Pig saw what occurred and ordered him to carry King Pig on his throne back to the Pig Palace.
After that, the birthday pig walked into the castle after King Pig, who had a giant cake in the dining room. The birthday pig saw it and thought it was meant for him while Ludwig van Beethoven's Symphony No. 9 played until King Pig ate it all. A piece of the cake fell next to the birthday pig, exciting him but just before the birthday pig could eat it, King Pig ate it too, much to his disappointment.
When night fell, the disappointed birthday pig went back to the building he slept with his fellow pigs. Just as the lights went off, a smaller birthday cake was given from them to him as a surprise party for him with the candle lit and the occupants cheered for the birthday pig while Symphony No. 9 played.