Beings of Tash Kalar
Just look at the picture. Do we need to say anything more? :)
Another of the Empire's gunpowder cards. Their common aspect is that they do not distinguish between friends and foes. The Cannon destroys all common pieces in the chosen direction. The upgraded pieces do not stop the fire, as the card would be too weak then; just imagine it bombards the entire line with sharp shards that destroy only the common pieces.
In a two-player game, the Cannon is not very strong if the opponent is aware of the fact you may have it. It is still useful to stop some tasks, like chains or Line Dominance.
In a melee, however, it is a very useful card. Not only can it kill common pieces of various colors over the board, it can also kill an enemy common or heroic piece on the summon square when using improvised summoning!
The pattern looks very natural, but it was not always like that. Originally, the cannon resembled more a cannon from Space Invaders (i.e., the same shape as the Hill Giant, except the summon square was on the top piece). During development, it was found weaker than expected and the requirements were reduced by one piece. The shape changed to the final form.
Also, the card was called Dwarven Cannon during development. Influenced by Warhammer, Warcraft, etc., I was thinking of the gunpowder part of the Empire as dwarven. It was removed as unnecessary... And, well, also to save dwarves as an option for some future decks. :)