Hellgrammites are widely found in ponds and rivers, and trout and other fish will eagerly eat them if they see them. This lure design is made to be used with a soft TPU, like Ninjatek's Ninjaflex (Shore A 85). Harder TPU's may not yield as good a lure.
Design wise, the line is meant to pass through this lure - the line-through hole extends from the nose to the tail. The side to side cuts allow the body to be extremely flexible. The thin legs wobble in the water if you use soft TPU. The little paddles on the legs contribute to some “lifelike action” when trolled.
The author marked this model as their own original creation.