A) http://pery.deviantart.com/art/Larry-the-cow-21015517?q=boost%3Apopular%20larry%20gentoo&qo=3 B) http://lucinka.deviantart.com/art/my-linux-desktop-24445598?q=boost%3Apopular%20larry%20gentoo&qo=8
Author seems to be Nafarius, see his forum post here: https://forums.gentoo.org/viewtopic-p-1846177.html#1846177 I have contacted him on 2011-06-12 via e-mail.
Update: got reply from author now. Binary images are back up at http://www.dreamshade.net/gentoo/wps.html Licensing and source files remain to do.
In the meantine (on 2011-08-15) Nefarius sent me an SVG file of that Larry alone. I just integrated it at [1]. As we still need a CC license for the actual wallpapers from him I have just mailed Nefarius again. [1] http://www.gentoo.org/proj/en/desktop/artwork/artwork.xml#larry
Just sent another mail to Nefarius. If I do not update this bug by 2014-04-10 it can be closed as fixed or wontfix, depending on your view.
Is this still in progress?
Closing as wontfix as announced earlier. Feel free to re-open.