Best part is the strip still works pretty well even if he had. You lose the wordplay layer of the joke, but with a mild re-contextualization of Hobbes in the second panel, everything else goes fine. Calvin would call himself a prodigy, Hobbes might muse that many children are full of themselves, and there’s still a burn to be had for the punchline. Plus the art, while typical for C&H, is actually somewhat visually interesting and pushed tiny daily newsprint strips to their limit.

I remember this one from childhood and that word was translated to spanish (at least latin american spanish) as “progenie” and I was like “what’s a progenie?” and by the context I just kind of assumed that it meant someone super smart or something, but never saw that word before (and never have ever seen it used somewhere else). Then after some years I found that same strip and re-read it and assumed they mistranslated “prodigy” or used that ‘obscure’ word “progenie”. It’s only until now I realize that nope, that sort of came in the original.