Why the mangaka was very displeased in the beginning with the anime adaptation, because it indeed differs a little too much from her original work in some aspects.
In the anime Panda is lazy, profiteer, and boundary silly, if not simple-minded at least. While in the manga, he likes to laze around but not as excessively shown as in the anime. He's much more reliable than he appears to be, and he's everything but stupid.
Penguin is just a minor character in the manga while in the anime, he's way too much present, which by the way annoys me to no limit. I wish they had keep him as an extra, that would have been way better. I find him useless and annoying because he's such a nosey, while nobody knows nothing about him, despite him being a regular at the café.
Concerning Shiro Kuma & Grizzly, they are more or less the same in both anime and manga.
The thing I didn't like about the manga is how ridiculously short the chapters are, not even 10 pages. I gave up mostly because of that. And lastly, wether it's in the anime or the manga, the puns are what I hate the most after Penguin character, because they were trying so hard to be funny, every single chapter and episode, that it became overuse and lousy very soon.