Is there any documentation detailing the gender of the Midgard Serpent Jormungand?
is it Male, Female, Both, Neither, Null, etc?
Jörmungandr is referred to as a "he" in translations of the Prose Edda, such as (quotes, in both cases, from this text):
When they came to him, straightway he cast the serpent [Jörmungandr] into the deep sea, where he lies about all the land; and this serpent grew so greatly that he lies in the midst of the ocean encompassing all the land, and bites upon his own tail.
To go a step further, the use of the pronoun "he" is not incidental, the old norse text for the above line is:
Ok er þau kómu til hans, þá kastaði hann orminum í inn djúpa sæ, er liggr um öll lönd, ok óx sá ormr svá, at hann liggr í miðju hafinu of öll lönd ok bítr í sporð sér.
Where "hann" is a male pronoun, analogous to the English "he".