So the other day I was reading some spell descriptions, just for fun. I reached the spell "Pass wall" (or pass through wall? Something like that), and the component was a Sesame seed. This gave me a good laugh, and I wondered how many other Easter eggs like this there might be, or inside jokes, in the books. Preferably only the rule books, as Easter eggs from adventures might give spoilers. I can only imagine how many there could be in the MM.