who is shocked to see a pig walk on two legs

The rest of the animals on the farm are shocked.

Everyone is shocked, though the first to see them walking was Clover.

"There was a deadly silence. Amazed, terrified, huddling together, the animals watched the long line of pigs march slowly round the yard. It was as though the world had turned upside-down. Then there came a moment when the first shock had worn off and when, in spite of everything - in spite of their terror of the dogs, and of the habit, developed through long years, of never complaining, never criticising, no matter what happened - they might have uttered some word of protest. But just at that moment, as though at a signal, all the sheep burst out into a tremendous bleating of -

‘Four legs good, two legs better! Four legs good, two legs better! Four legs good, two legs better!’