The Spleenrippa is an Ork dedicated anti-tank vehicle. Its primarily armament is a large Battle Cannon, but it is also equipped with a variety of Shootas.
It is also contender on one of the most weirdest, goofiest and impractically designed vehicles of the Orks. Which is saying something since it has wheels, which is probably really bad at compensating for the immense recoil coming from the giant gun.
Nowadays it is being mothballed by Games Workshop and has been sitting inside its closet for over decades now.
If you want to put this into proper modern WH40K tabletop than it is best to find a Trukk, rip out the main chassis and replace it with a giant pipe/cannon sitting comfortably on a metal sheet, give its FA/SA and RA with an equal range of 10 and viola! You have a working Spleenrippa. As a dedicated anti-tank vehicle, it is best to position it very far away and not let the enemy to get to close.