Who-ville was an Imperial-controlled planet on the distant edges of the Goatronium Expansions. The indigenous population of Whos were renowned for their kerplinkas and what-woozlers, Christmas carols, and delicious roast beast. Neither they, not the local Imperial garrison, was expecting much trouble.
However, on top of near by Mount Crumpit—ten thousand feet up—lived a mean old Ork warboss—da Grinch— who HATED Christmas.
"I gotta stop Christmas from coming," da Grinch said. "Perhaps if da hummies and Whos wuz all dead?"
And then he got an idea
a horrible, cunning, Orky idea. "I knowz what to do," said da Grinch to pal Maxx. "We load up with dakka and trukks full of boyz, den dakka dem impies until dey can't make no noise!"
Battle report at: the Goatronium Expansions