Nope! You do not need to peel zucchini! Not just for these muffins, but ever. If you have a super picky family member who might balk at any sign of a green fleck, then ok, I give you permission to peel them, but otherwise, don't create more work for yourself. If you are worried about pesticides in the skins, be sure to buy organic. And either way, always wash your produce really well!