6inchmove for the photo. I recall when the new Tyranid codex came out, after many of the old nid players were done ranting, folks began to talk about the tyrannofex and how it was too expensive for BS3 and a poor weapon skill. Many of those folks continued to dismiss it on the unit v. unit basis, comparing it to other codices' staple heavy support units like long fangs, broadsides and more.
The truth is that it isn't terribly accurate, only hitting half the time. Even then, without AP1, you aren't garaunteed to actually take any tanks out of the fight (go ask a dark eldar player how their dark lances have been doing, yeah, that's why heat lances to the codex!) - "So why not just take Zoanthropes and be done with it, OST?" Well because there is more to this giant than a big ass gun and like any other tyranid unit, it functions best with synergy ...
Before we embark on the synergy quest, let's take a look at the T-fexes weapon options;
For the basic Tyrannofex cost of 250 points, we get a big template weapon similar to the hellhound's main weapon in that it can be thrown. At S6, it isn't too bad and at AP4, Marines will laugh at you, but few others will. The real problem though is that almost every entry in the tyranid codex is good at killing infantry and while we aren't great at busting cover, this isn't really the most cost effective weapons platform for the job.
The fleshborer hive is the next weapon weighing in at 10 points and to be honest, to take a 12" 20 shot fleshborer on THIS bug, you would have to take at least 10 points OFF the cost of the model. 20 gaunts have just as many shots, score and have fantasic synergy with Tervigons that allow them as a squad to be even more effective than the T-fex in CC situations. While the Acid Spray has some attractive features, this gun is trash.
Finally, the gun that gets everyone hot and bothered, the Rupture Cannon. For 15 points, you get two shots at S10 from 48" away. The drawback is that you have BS3, but the benefit is there is no weapon that can damage tanks as well as this from across the board. Zopes can do it better, but they also have psychic tests and have to be close. This cannon is mounted on a six wound MC that can shake off the all-to-common missile launcher spam. If that was all there was too this beast, then it still wouldn't be worth the price, but there is more ...
The T-fex also has a thorax ,mounted template weapon with three options. I am not a math wizard, so I look at it like this:
Electroshock Grubs: S5 AP5 - Great for killing guardsmen and Eldar and decent at wounding Marines (just not for killing them).
Dissecator Larvae: S1 AP -: Wounds on a 2+ so is great at wounding anything that doesn't have an AV. AP nil is a little bit of a downer, but the potential to cause a large number of saves balances it out.
Shreddershard Beetles: S3 Ap - Rending - honestly, the things it wound well, don't really pee their pants over rending. The stuff that it would rend, laugh off regular hits from it.
-Personally, I take dissecator larvae, but that's me. Any of these are decent choices. The key here is also that they are template weapons and do one thing the rest of the codex doesn't do very often - ignore cover.
Now the last choice you have is between the 4 shot stinger salvo ir the large blast cluster spines ... hmmm ... yeah, I'll take the large blast.
Now we have an MC that is VERY durable to all but the lascannon and the mighty plasma gun, rocking a S10 weapons, moving down the board every turn who GETS DEADLIER TO INFANTRY THE CLOSER THEY GET (which happens to work well with the fact that he pops vehicles from far away). He has duality (which is ideal as some of our options in this book have to rely on synergy for duality), he has the guns, but he really lacks assault, which leads to synergy, which leads to the type of army that best lends itself to the tyrannofex:
I'm not going to write a better list or say I can, so follow this link to 3++'s list here and then get back to us for the exiting finish!
Now these lists bring a lot to the table, but what they really takes advantage of is the mutual support and synergy of it's units. It becomes much more than the sum of it's parts, when you can press into vehicle with raveners aftercracking them open, only to follow up with preffered enemy guants, the tyrannofex or even the swarmlord himself. Bringing so many walking points to the table obviously means your army benefits more from a walking theme and while Swarmlord is awesome in these lists, keep in mind that you could march up th board with an armoured shell Tyrant with Old Adversary and maybe a shooting weapon, so that after all your shooting and walking, you can get into assault as a big pile of preffered enemy MCs. Nobody you fight will make the tyrannofex look bad in CC when they get Paroxysm cast on them and the T-fexes have preferred enemy!
Another way, a more agressive method, of running the T-fex is to push them up the board with Onslaught from the tervigons, pushing them right into the mid board early, setting the rest of your walking horde up with a tough group of targets for the enemy to shoot at.
One last note before I conclude. Don't bother on Adrenal Glands (I2, seriously?) or poison sacs (again, really?), though if you have tons of extra points or if you feel the cruel need to toy with your opponents emotions, regeneration is somewhat worth it at 20 points, though I would just spend it on my termigants (the best troop choice in the game lol).
In general, I would wrap this up by saying you need to play to every one of the T-fexes roles - he is a jack of all trades and a master of none, so if you only bank on one facet, it will never pay off in effectiveness. The T-fex runs well at a 1750 minimum, better at 1850, 2000 and of course 2500.
Good luck and happy hunting with your T-fex. Comments, critisism and feedback are always welcome.