The center panel (Utopia) of his most ambitious work "Garden of Delights" has got to be my favorite. Every time it is examined, it expands the mind in new ways, causes new questions to be asked. For instance:
But what is this? I declare...a man-eating mussel. My first thought involved the mussel forming men instead of pearls around a central kernel of junk, but there are pearls inside already. Maybe the man (lets call him Steve) climbed in to get some. And then Bob (the guy carrying him) is trying to help in some way. Or he's hungry for a little stir-fried mussel and just took advantage of the situation. Either way you look at it, something awfully strange is going on here.
(or the unthinkable...the rest of the panel is filled with folk copulating...perhaps we shouldn't be so specie-ist)
This one is just odd.