The giraffe in the first picture looks very curiously. The picture can be touched to resize, just the picture.
The hippo is very busy not to leave anything from the huge stack of hay it has for lunch. The photo was made partly before and after the meal.
The Fish in the photo at the bottom is remarkable. A Fish does not speak, but this one might tell a lot. The plate next to the basin tells that it is an asian fish what makes it a litte harder to figure out what the fish wants to express.
The letter in the middle, next to the eye, looks like the chinese character "chuo" or "center", indicating that the text describes the part of the body where it is located. As in some asian languages the characters are written from right to left, the word "center" might be the beginning of what it says, but would this make sense?
Taking recent results in gene technology into account, one could as well assume that the creature carries a message that was introduced to its genome, some message that could even be against the interest of the fish itself.
It might be a short instruction like: "open here". Further possible short instructions might describe the way to prepare it or what sort of wine suits best to it. I came to this interpretation by looking at the grim on its face.
On a final thought one could conclude that this species of fish with its message has survived in free nature, while one representative has been brought to the zoo where the message has not been manipulated. So the message has proven to be helpful for survival. That means it must be a statement like: "Do not eat". At least this would also explain why this sort of fish just survived in Asia.