I haven't seen any poses for any of the penguins in Poser.  A penguin really doesn't have the ability to do very much so far as their body positions are concerned because they are basically really fat birds that can't fly.

To pose a model for swimming would be pretty easy.  Lift the neck and head so that it's in line with the body. Point the legs/feet backwards towards it's tail and that's pretty much it.

And so far as walking goes, they waddle and their feet are actually covered by their body, so if you see a still shot of a penguin sitting and a still shot of one in the process of walking, they will look nearly identical except perhaps for the fact that they are leaning a bit in the walking one.

"It is good to see ourselves as others see us. Try as we may, we are never
able to know ourselves fully as we are, especially the evil side of us.
This we can do only if we are not angry with our critics but will take in good
heart whatever they might have to say." - Ghandi