[That's a big question. One that will no doubt require some thought.]

Yotsuba has seen cows before, they're big and black and white and you should clap when they give you milk, the cow did a good job! And elephants! They're really big and they come from In-di-a, because they're indian elephants. Ohhh, and dolphins! And penguins, I really like penguins! Have you seen a penguin before? A penguin can slide on its tummy and go whoosh! [...] But Captain Jack told Yotsuba about scary penguins, so dolphins. Dolphins please!