Piro speaks:
its more of a cross between a knit cap and floppy kitty ear schema i've doodled before. i thought the 'sad kitty hat' idea was cute
on a side note, its similar to the Digicharat GemaGema army hats, but not really. If you look thu Koge Donbo's illustrations of Dejiko, you'll see her wearing a variety of kitty-style hats, some of which are close to this, but none of them are knit caps, if i remember correctly.