LOL, too many blue characters named Penn:
https://www.furaffinity.net/view/6089517/ https://www.furaffinity.net/view/713450/ User named Penn (Blue otter)
https://www.furaffinity.net/view/3624877/ Kyuushi's Penn is the RED character, so definitely not the right one!
https://www.furaffinity.net/view/6519097/ https://www.furaffinity.net/view/7857232/ Another that Wolf-Mutt drew...

I've fairly certain that it's the user avatar in a later revision of the design, but wish Penn hadn't taken down access to their FA gallery. Grr, makes history/research a pain!