Anybody else got a clue...?

As you might have noticed, i've been digging through old files for the blog, pulling out things that have been sitting around for a bit.

I'm not always the most organized person. I still rely on old habits from when my mind and i were a constant team and little things like notes and labels were not important. So i got confused when i hit this piece of art from the great Joe Sinnott, with no damn clue from where it was pulled - the only label is SinnottSSTB, and it's in a stack of things i was pulling from 1977. Is that the year it's from? Is ThunderBunny that old?

And just, in general, WTF?

I suppose i'll eventually stumble back across the source, but that could be a very long time from now. Anybody else got a clue about the origin of this piece?

art by Joe Sinnott for ... where you not paying attention?