I am 99.9% sure that pachyderm is another way of saying elephant. You could change it though so it would be different, because there are different kinds of elephants. I would say a "rogue male elephant" would probably be what your looking for. I'm not being sexist, but those are the ones that are bad news. I think it would probably be the hardest hitting offensive form, trample, gore, and headbutt being some skill options. However it would dodge ZERO I think. Heck of a trade off, huge hits, but take every hit dished out at you.

Resistance to all damage (regardless of align or attack type), because of skin thickness. And believe it or not, quiet movement in the wilderness. It's been scientifically proven that elephants have the most potential for walking silently, because of how they're feet are made. An elephants foot bone structure keeps it constantly walking on it's toes (literally), and it walks on a huge round pad of cartiledge. So an elephant makes almost no noise when it walks.

just some additions

Jasmin