The Kids from Room 402

There Must Be a Pony (1x19)

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Polly becomes popular when she gets a pony, but as the kids all take turns to meet Snowball they find out that it's not as great as they thought as Polly forces them to answer questions on ponies before she will let them near it. Meanwhile Jessie pretends to have sent his book report to his Nanna and Pop-Pop's by mistake to stop Miss Graves from grading it.