Wartrakk Gunner for a Trukk or Squiggoth…
If you get an Ork Skorcha or Grot Bomb Launcha, you also get as a result a spare Gunner.
This is one I am in the process of painting up.
I am going to use it on either a Trukk or my Squiggoth.
It is a pity that the rules/codex don’t allow you to use more twin-linked Big Shootas.