On 2009 April's Fool's Day WotC made available this "missing" adventure form the Dungeon Delve book—originally set for party level 2 1/2!
It is a free download and it is written in a very humorous tone with surrealistic and/or fluffy monsters of various kinds!
In a time long before the current age of the world, fomorians began magical experimentation with myriad life forms, fey and otherwise, to produce nefarious guardians and soldiers. Such experimentation inevitably results in successes and failures. Loath to part with their failed experiments without sowing some form of wickedness, the fomorians devised mystical prisons for their underwhelming monstrosities. These they built upon or near the surface of the world, where their castoff pets could do harm to the fomorians' enemies.
These "prisons" are dens of madness and confusion. Little, if anything, can be expected to make sense within them. The adventuring site of this scenario—the so-called Fool's Grove—is no different.