Poser comes with a Dog, Cat, Horse, Dolphin, Fish, Frog, Lion, Wolf. Dinosaur and a Rattlesnake.

These are pretty low rez and not very realistic out of the box, but there are quite some freebies out there that greatly improve them, especially the horse.

There are also several third party animals out there that you have to buy extra.
As they are generally higher rez they are more realistic, but need better hardware because of their larger polycount.
And even some of the most expensive ones still have issues with anatomical correctness.

So it depends what you want to render.
If you need just a few common animals as "sidekicks", the default Poser animals would suffice.

If you want to render pictures or tell a story focussing on a certain animal, you should plan to spend some extra money for one of the third party animals.

stahlratte