Download Problems

[Videogamegirl101]

Please excuse me as I am new

But I have tried for days downloading Zoo Tycoon 2 Animals. I've put them in the main ZT2 Folder just as the tutroials said to do.
But everytime I load up ZT2, I don't get the name of the animal but "1" and its really confusing me. They are all ZT2 files and nothing else. They've been in Z.I.P folders.