Swarm of the Century is the tenth episode of the first season and first aired on December 17th 2010.
Writer: M. A. Larson
Episode Summary
In a nearby field, Fluttershy was gathering flowers, finding the prettiest ones for Princess Celestia, who was planning to visit Ponyville. She then noticed a strange yet adorable creature from the Everfree Forest. While it had eaten a large basket of apples despite its small size, it didn't seem to deter Fluttershy from its sheer cuteness. She took the new creature with her to show to her friends.
In Ponyville, everyone was also preparing for the royal pony's arrival, including Twilight Sparkle, who wants everything to be perfect. Fluttershy shows Twilight and Pinkie Pie of the creature she found. In fact, even she noticed two more. In awe, Twilight decided to take one off her hands so Spike can have a companion to keep him busy. Pinkie, however, backs out in disgust, recognizing it as a "Parasprite". She left, saying that she needed a trombone. Shaking off their confusion, the other ponies continued their work with their new friends, while showing the insects to the others who had taken one for themselves.
The next day, Twilight woke to see hundreds of Parasprites in her home. While she and Spike had no idea where they came from compared to the one they had, they noticed the creatures making a mess, tossing away books and parchments. Rainbow Dash's set of the insects began attaching to her. Rarity seemed to had grown with her swarm, until she saw that they reproduced by coughing/sneezing out other bugs, to which the glamorous unicorn became disgusted with them. Even Fluttershy had trouble communicating with them (or in her case, begging, pleading, beseeching, etc). Fearing that this will most likely ruin Celestia's visit, Twilight realized that this sudden infestation would be more than a simple nuisance. And worst of all, it was multiplying by the second (literally)!
Meanwhile, Pinkie was gathering random musical instruments, including a harmonica, a banjo, and a pair of maracas. No one really knew why, so they assume she was just playing around.
The ponies call on Applejack for help, using her herding skills, to round up the pests. They succeed in driving them back to the Everfree Forest. Unfortunately, Fluttershy thought of keeping just one Parasprite in her house. That one bug burst out into thousands, and the ponies were right back where they started. Rainbow Dash tried to gather the second swarm by creating a tornado, until Pinkie came back with a pair of cymbals. Dash dodged the cymbals, but the distraction broke the tornado and released the swarm onto Ponyville. They rush to stop the infestation, ignoring Pinkie's attempt to explain why she was gathering the instruments.
They arrived too late, watching in horror as the Parasprites eat all the food in the town. Twilight decided to cast a spell to prevent them from eating the food, and it worked. But instead of making things better, they became much worse. The bugs soon began eating everything else: signposts, lamps, Rarity's ensembles, and even the words from Twilight's books. Twilight showed a Parasprite to Zecora back in the Everfree Forest, who recognized it. But not even the zebra knew how to get rid of them, only stating that because of their locust-like behavior, Ponyville was doomed.
Twilight became overstressed from the crisis; Ponyville is in the midst of chaos from the Parasprite infestation, and the princess would arrive any second. Just as she started making a highly irrational plan (building an exact replica of Ponyville next to the real one in less than a minute), Pinkie Pie arrived as what seemed to be a one-pony band, with all of the instruments she gathered during the crisis. Before Twilight suspected another one of her games, she discovered the swarm were attracted to the music and were following the pony away from Ponyville. The other ponies meet Princess Celestia near the town's outskirts, who saw the lined-up bugs as a parade. She informed her pupil that she needed to cancel her visit to deal is an infestation in Fillydelphia, full of "incredibly bothersome creatures". She asked Twilight if she would like to give a report on friendship before she left. At first Twilight couldn't think of one after everything that had occurred, but after seeing what Pinkie was capable of, she said that the best solutions can come from the least likeliest of places, and it was a good idea to listen to her friends opinions and perspective, even if they don't make any sense. Commenting on how impressed she was with Twilight and her friends, Celestia took off.
After apologizing for ignoring and underestimating Pinkie, the ponies returned to Ponyville.
Or at least, what was left of it... Template:Episodes