Apparently it's pretty well known in the zoology community and shows up fairly often in enrichment journals (giving zoo animals things to entertain them, make their lives more interesting, etc., is called enrichment). My sister's housecat will climb humans after watermelon, and our childhood cats adored muskmelon, so it didn't strike us as all that odd but we have specialized experiences to draw on.

Freddy and Jackie also like oregano, and straw that had been used by various sorts of farm animals (miniature horses, donkeys, llamas, etc.). The keepers would stuff burlap bags full of the used straw and chuck them into the enclosure for the cats to play with. A full-grown cougar playing with a burlap bag stuffed with dirty straw looks remarkably like a housecat playing with a catnip mouse.