More than a year ago I wrote on my to-do list to sculpt Larval Cell and hopefully place it in a water tube. At that time I sketched up some schematics for the water tube and i actually sculpted a quick prototype out of modeling clay.
Reference images and others can be found in my previous post:
Cell: Larval Form 1
So, in the image below you can see the prototype sculpted by using a couple of images taken from the actual anime episodes.