As part of my speed building last week for the Apocalypse game I wanted to get a Tervigon in the army. I had three unbuilt fex kits so I got to work. My goal was mainly just to get the basic body assembled and do the greenstuff and arms later.
My conversion is really simple. I essentially just extended the mid section of the fex kit with spure pieces. I then started to fill in the space with random curvy bits just to that there is less greenstuff required.
I used some of the hive node terrain bits from the stealer set to get the places where the termigants will appear.
Once I do the greenstuff I will add another armor plate to the back just facing the other direction to cover the unfinished spine part.