Sci-fi children's books

The best mashups respect all their sources, reflecting each back on the other/s.  Each one of these from CollegeHumor is good, though I think the Dr. Seuss is the weakest of the bunch just because it's easier.  The Star Trek/Frog & Toad makes me happiest, but I think the best is the Berenstain/Battlestar Bears:

It's got the publisher's imprint, the corners, and the cigar.  And the previously unrecognized resemblance between Edward James Olmos and the bear dad!