Mammoth

Possible Mammoth Spoilers!

These are rumour at the moment. Until it shows up in war room these stats could be wrong (but probably aren't, the gun at least is not wrong and the rest is very believable).

Fury:4

SPD:4

MAT:6
RAT:4
DEF:8
ARM:20

(2)P+S:19 Fists (crit pitch)
P+S 17 tusks

RNG 10, RoF 3, AoE 4, POW 15 gun
Assault
Bulldoze

Animus: Repulsion.

Straight up looking at those stats it's good. Good P+S, lots of initial attacks, decent MAT, great animus especially when combined with bulldoze and an awesome gun. Then you add in the support Skorne can give to their beasts and it's amazing. With rush and road to war (or rush and abuse and with abuse it's 23, 23, 21 which is stupid good) this thing is SPD 8, faster than the archangel which has no usable SPD buffs. Or you can leave it maxing out at SPD 6 with rush and put defenders ward or inviolable resolve on it to take it to ARM 22 with an agoniser and a krea behind it to make it even more invincible. It will happily sit in front of a Krea, with an ARM buff spell and far strike (from the cyclops raider) and blast anything else stupid enough to walk into the scoring zone. If it is shooting at a unit with black spot it can potentially make 6 shots with the -2 DEF taking it to equivalent RAT 6, if it's aiming which it can conceivably do with far strike it's RAT 8. 

There is so much this model can do with so many casters. Of course the problem is going to be its cost and the fact that it is competing with with a lot of other beasts for its spot. That said this guy is awesome and he is going to turn up in a lot of lists. Easily the best of the Gargantuans so far. Certainly not invincible though and the model from what I have seen looks sweet. 

Just a note on bulldoze + Repulsion. Let's assume you only have rush. No zone is going to be bigger than 12" in any dimension in 2013 so that means the Mammoth if near the centre of a zone can walk over, push every enemy model in the zone 4" away and then still make all three shots with its gun without giving up defenders ward or any other upkeep spell on it. Or if another colossal is in the zone charge it, do a crap ton of damage and then push everything else out. It will depend on the colossal and which caster you have brought whether the free boost from the charge, 4 initial attacks at high pow and two bought attacks will be enough to kill it. With Xerxis with the feat and fury you will kill the archangel or an unbuffed Mountain king with your initial attacks and have significant damage to spare.

If you are going to be up against this thing my advice is to make it a priority to kill it but the standard colossal advice still applies (that link has been updated slightly now to correct the Gorman mistake).