Jade Hare was produced as a freebie module included in orders from TSR's Mail Order Hobby Shop.
Some were produced with the standard card stock covers with original color art found on all modules.
A vast majority were released without covers. This module was released to support the black box basic rules edition.
We don't believe the ones with covers were given away. But of course we might be wrong.
"Wherein the intrepid adventurers confront the Mad Warlock Abu-Ghabar and his evil minions to recover a priceless and ancient Jade Idol."