To call someone a pumpkin-head is of course to say that he is a fool or dunce; to imply that his head is as large or as empty as the garden gourd. But there have been three great pumpkin-headed figures that, if all foolish in their own way, have proved to be lovable and popular in literature and popular culture, and they all seem to be in an ancestral line.
"The grandfather of all [pumpkin-heads] in fiction is Feathertop, published by Nathaniel Hawthorne in 1852. Feathertop is a scarecrow constructed by the witch Mother Rigby, who animates him by having him puff on a pipe fired by a coal supplied by her imp, Dickon. This not only gives him life but makes him appear human to those that see him: the harder he puffs the more real he appears, and when he slacks off the straw begins to appear. Mother Rigby sends him into the world, where his handsome illusory appearance makes him prosper, and he falls in love with a beautiful girl and almost marries her.
*quoted from my own post on Scarecrows.