One shell, Two shell; Red Shell, Blue Shell.

So far, the Subterran Uprising have proven to be a force that will pimp slap you harder than a brick to the face, and that's because they can't hold bricks and have to compensate for that.
With every army, there has to be a balance. You can have an army full of "I'ma cut you" units, or a force that walks up with a little flag and says "It would be quite nice if you stood over there while we shoot you. No, back a little further please. Thank you".
It's always an option for each faction and the Subterrans are no exception.
I introduce: The Mollok Mortar.
This cute little guy is absolutely stylin with its very own turtle shell, complete with rifle attachment. While his speed is not the best, the cheeky blastard makes up for it by burrowing across the world and making himself inconvenient to other opponents.
But where he excells in movement, he improves in shooting capability. His Blast stat is slightly better than a Spitter: 2*1, Short Range. An additional action die to an attack can always be useful. But the Mortar gets better with a Blast Trigger!

Power Drain: Target monster's controller loses one power die.

Nifty Huh? Now to get into range... Wait a minute. We only have short range.
So these Grunts are better than your standard Spitter Grunt, right? But you never field a Spitter Grunt on it's own, you always have an Elite available. With a new faction and playstyle comes a new unit layout. Lords of Cthul had a reputation to have Elites that grant Abilities to adjacent figures. Squix "Force Field", Corruptor "Overload", Spitter "Radar".
The Mollok Mortar Elite doesn't grant that. He promotes capability with Officer, and is stuck with short range as well.
So why not field an Elite Spitter with them and give off the Red Radar?
Cost efficiency. If it were possible to think ahead in a game and prepare for it, feel free, but a slow and unmaneuverable unit that doesn't benefit the Mollok Mortars attack aside from offering Radar isn't quite worth it. You're better off fielding Spitter Squads and having a Mollok Mortar Grunt available for the Trigger. Or you can field a Radar Array in your forces.
The Mollok Mortar also doesn't ruin the Subterran's Reputation to backhand it's opponents. With a 2*0 for it's brawl attack, while it may be mathematically worse than a Mollok Brute, a Berserker can kickstart that in a pinch.

So while the Mollok Mortars aren't as self sufficient as the Spitters, they can still put a nice dent into the enemy and their motives. Later, I may update this with the Glass Mollok Mortars Details.