It's a ... — 英语阅读题

读短文，回答问题。 Today is Sunday. Tom and his mum go to the zoo. Tom is very happy. At the gate, he sees a big animal. It has a long nose. Tom says, "Mum, look! It's an elephant!" Then they see a small animal. It says "Miao, miao." Tom laughs and says, "Ha! It's a cat. How funny! A cat in the zoo!" At last, they see an animal in the water. It has no legs. Tom says, "It's a fish! My favourite!" 问题：Tom 在动物园一共正确说出了几种动物？请写出他说的话（用 It's a/an ... 句式），任写一句即可。