While the Orks tend to have the biggest whatever around because that's what they do, the Imperial navy certainly likes to go big as well. Such is the case with the Marauder Colossus, coming soon to Aeronautica Imperialis.
From the article:
Here at Flight Plan Headquarters, we like things that make a big bang. Shocking, we know. Luckily for us, the Imperial Navy – never ones to be outdone by their Orky opponents – has seen fit to deploy its largest bomb yet. It even comes with a whole plane attached!
Conceived by the assuredly sane and stable Tech-Priests of Cypra Mundi, the Marauder Colossus deftly answers the question of “What if we stripped everything possible out of the Marauder and replaced it with a 10,000kg drum of high explosives topped with a melta warhead and diamantine tip?.” Designed to crack the toughest targets above and below ground, this new addition to the Imperial Navy’s arsenal is sure to find a starring role in your next ground attack mission.