A Dimachaeron is a new giant Tyranid monstrous creature and is essentially the Tyranid version of the Eversor assassin, with steroids. It appears indeed to have been evolved only to slaughter those identified among their prey as leaders in the midst of battle, spreading terror and dismay among the ranks of all who resist the Hive Mind's advance. Contrary to the Lictor, whose approach is stealthy and slow, the Dimachaeron throws all subtlety out the window and relies only on brutality and animalistic rage to destroy anything the hive mind wants dead.
For some reason, the Hive Mind thought it was a good idea to warp the Dimachaeron's ribcage into a gigantic maw. While some may say two mouths may be better than one, lets be frank here. What is the point of the primary head if the ribcage-mouth-thing has a maw that can OMNOMNOM more things than it does? A waste of biomass if you ask us.
On the Tabletop
The Dimachaeron is a murder machine. That's it. It has 5 attacks base (6 because it has two melee weapons) is WS 8, strength 6 and initiative 6 and come equipped with Adrenal Glands and Rampage to make it even more frightening. Then there are its special rules and equipment: it is a leap monstrous creature and can choose to leap in the movement phase or in assault (The first works like jump infantry, but with only 6" range, the second gives him +1S HoW with Strikedown) and it has two close combat weapons. The grasping talons are S+1 AP2 Talons that, when it rolls one or more 6 to-hit, gives an attack on an unwieldy S+4 AP1 ID claw that can kill anything smaller than Extremely Bulky, while the Sickle Claws are an AP2 pair of claws with 4+ ID, for when you really want to kill that Bloodthirster. Furthermore, if you chose to use its grasping talons and kill one model with the thorax spine-maw it gains a number of plasm tokens equal to the model's wounds and that goes away starting from the end of the following turn. Until it runs out of tokens, it has the FNP (4+) special rule, meaning it can be a terrifying DISTRACTION CARNIFEX!
Keep in mind that it has instinctive behaviour (Feed) but that shouldn't be that big of a problem given that it's LD 10. It also isn't fast, even being a fast attack attack choice, and will attract a lot of fire for its ability to obliterate everything it bumps into short of a few special characters, so consider to embark it in a Tyrannocite and drop it in the midst of the enemy army. It is a risky tactic, but your opponent will be quite hard pressed and will have to choose if he wants to concentrate fire and obliterate it immediately, letting the rest of your horde close on him, or let it live and see his army ripped in pieces the very next turn.
Tactics to counter Dimachaeron
Lots. Of. Plasma. Due to T6 and 3+ save, plasma guns and equivalent are essential for killing any Tyranid monsters, but even more so with the Dimachaeron. Instant death weapons such as Huskblades and Beast Hunter shells work well against Dimachaerons due to lack of Eternal Warrior, even if it has plasma tokens as ID ignores Feel No Pain. Dimachaerons should be your priority targets if they pop up due to transporting as they can cause metric buttload of damage to all but the most dangerous melee units in the game (such as archons with huskblades, Knights, maulerfiends and suchlike). If they are at range, however, concentrate firepower elsewhere since comparably these jumpers are slow, being able to only move 6" and jump another 6". That would be pretty good speed, but it brings Dimachaeron out of range for Venomthrope's cover buff. And Dimachaerons without cover buffs die in droves.
|Leader Organisms:||Broodlord - Hive Tyrant - Swarmlord - Tyranid Warrior|
|Small Creatures:||Gargoyle - Genestealer - Hormagaunt - Ripper - Termagaunt|
| Biovore - Hive Guard - Lictor - Neurothrope - Pyrovore |
Ravener - Tyrant Guard - Venomthrope - Zoanthrope
|Monstrous Creatures:|| Carnifex - Dimachaeron - Exocrine - Haruspex - Malanthrope |
Maleceptor - Mawloc - Tervigon - Toxicrene - Trygon - Tyrannofex
|Gargantuan Creatures:||Cerebore - Dactylis - Hierodule - Malefactor - Nautiloid - Viragon|
|Flying Creatures:||Harpy - Harridan - Hive Crone|
|Bio-Titans:||Dominatrix - Hierophant - Hydraphant - Viciator|
|Other Organisms:|| Bio-Weapons - Cortex Leech - Mieotic Spore - Mucolid Spore |
Mycetic Spore - Spore Mine - Sporocyst - Tyrannocyte - Zoats