I wanted a form which would introduce an arbitrary
element recurringly, with a hidden significance. So
starting with a text i once created using a computer
to randomize words ("Star Grope"), i numbered the words
& created a second matrix of numbered slots. The positions
that correspond to prime numbers in the matrix, i circled.
Then, for each prime-numbered matrix position, i wrote in
the words of "Star Grope" consecutively (in green ink). The
result was a fill-in-the-blanks form with every so often
a word that had to be used. The ensuing matrix can be used
for poems of any length or structure. After i've written
a poem using one part of the matrix, the next poem i write
begins where the last one left off. And at the end of the
matrix i begin again where i started...

The first set of matrix poems i wrote were in ABAB iambic
pentameter quatrains. The next ones, however, i put in a
syllabilistic meter of my own invention called "snowflakes":
each stanza has lines of 1, 3, 5, 7, and 9 syllables, in
any order. Further constraints suggested themselves: parts
of this series omit the letter E; some are composed using
only the words from a magnetic poetry set (& a few parts
use only the words from that set that lack an E). After a
single pass through the matrix, i sometimes would let words
from the previous matrix show through...

The entirety i have called "The Mothman Elegies". It is a
series that now, after three passes of "makrugh", seems not
quite at the point of changing into something else; & so i
am making these notes for closure, & to suggest further
exploration to others in search of a new way of constructing
longer poems.

As a poet who I challenged enough by the conventional forms, I can't promise to pursue this new one any time soon. However, one of the wonders of form is the way that it leads us places we otherwise wouldn't have gone, and sometimes simply trying a new form opens up unexpected sources of inspiration. (Richard Moore, a fine poet and essayist, has a collection of essays titled "The Rule that Liberates" that explores this and other seeming paradoxes.)
In some ways this new form sounds like a variation on the acrostic, where certain letters or words are required in certain positions, but an acrostic isn't randomly generated.
Let's hear from anyone who tries this one.
RPW

Any relation to Elizabeth Bishop's "The Manmoth"?

no, but derivative of "The Mothman Prophecies" in
a certain sense.