Stompa
A Stompa is what happens when an Ork Mek decides that its Mork/Gorkanaut is not stompy enough and that they need sumfing bigga. Essentially, the Stompa is a smaller version of an Ork Gargant and is an equivalent of an Imperial Warhound or Reaver Titan. Like most Orkish machinery, each Stompa is a unique effigy to their gods Gork and Mork, with each having a different layout and appearance to be distinguishable from one another. Like most Ork titans the Stompa is usually equipped with one close ranged weapons for extra killy (Such as an oversized chainsaw or a giant hammer to smash sum gitz!) and a various assortments of guns situated everywhere on the titan for maximum Dakka.
Variants
So far there are two confirmed sub-classes of the Stompa studied by the Imperium, the Goff Stompa and the Mek's Stompa
Goff Stompa
The Goff Stompa is essentially what happens when the Orks really wants to get in close and personal. Removing the main gun arm with an extra close combat weapon for extra killiness, the Goff Stompa was popularized by the Goffs (Who would've thought!). Usually a Goff Stompa can be equipped with a giant claw that can grab and throw tanks like a toy car while others are equipped with a giant steam roller to turn the enemies of the Orks into a red paste.
Mek's Stompa
The Mek's Stompa (As its name suggests) are often created by a overly ambitious BigMek (Or even a group of them) and are often seen as a direct opposite to the Goff Stompa in its battle role. Switching its close combat weaponry with even more Dakka, usually armed with more massive cannons, rapid-firing Gatling guns that spew out tank shells, an assortment of lesser guns and sometimes a plethora of different rokkits, some piloted by Grots (willing or otherwise). For defense, a Mek's Stompa can be protected by a force field, but knowing the Orks, the chances of protecting it against other titans will result in much fail.
Supa Stompa
These are essentially suped-up Stompas and are thus, border between a regular Stompa and a Gargant. This makes it a clear analogue of a Reaver Titan. As expected, these larger Stompas are big enough to carry a Macrocannon and a Soopa Gun. Some in the Imperium has considered calling it as the deadliest weapons in the Ork Horde, despite the fact that there are larger Gargants with even more powerful weapons lurking around.