26 USC §5674(b) & 27 CFR §25.144(a) make it a federal crime for a brewer to remove beer from a brewery in a keg that has the name of more than one brewer on it.
21 USC §§331, 333 & 21 CFR §169.115(a) make it a federal crime to sell French dressing if less than 35% of its weight is vegetable oil.
43 USC §1733 & 43 CFR §6302.20(e) make it a federal crime to pick someone up from a federal wilderness area using a hot air balloon.
7 USC §8303, §8313 & 9 CFR §93.318(b) make it a federal crime to bring an American horse back into the United States after being in a Canadian rodeo without a health certificate.
42 USC §6928 & 40 CFR §257.3–8(b) make it a federal crime to start a dangerous garbage fire.
21 USC §331, 333, 343 & 21 CFR §155.201(a)(2)(v) make it a federal crime to sell canned "random sliced" mushrooms unless they were sliced in a random manner.