Body, and whose Hat was rather small.
Lear composed a longer and probably more well-known poem about the man with the large head and diminutive hat, "The Courtship of the Yonghy-Bonghy-Bo." A link to this poem may be found here: http://www.poemhunter.com/poem/the-courtship-of-the-yonghy-bonghy-bo/.
However, the shorter poem presented here, really no more than a caption accompanying the illustration of the hyper-cephalic hero, has a haiku-like, memorable quality that has always made me smile. Speaking as one who had the biggest head in his college graduating class--figuratively perhaps, but most definitely literally (I checked at the time)--I also cannot help but to identify personally with this humanoid version of Oswald the Octopus (pictured here accompanied by his faithful dog, Weenie).