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I was considering making a list utilizing one or more of the Tyranid's special characters. While technically an older edition, it sounds like they are still playable in friendly games at least. A few of them sound pretty interesting:
Old One Eye: Sounds great for being a "baitfex" with his ability to auto-regenerate and have a 50% chance to get back up after dying. Not to mention if he manages to get close enough to a vehicle it would be toast. If I'm not mistaken, at 199 points he'd also be cheaper than a standard baitfex.
The Red Terror: This one seems the most appealing to me. A Monsterous Creature that can deepstrike would be amazing for taking out tanks. Not to mention his speed and 3+ save make him at least reasonably durable for taking a few hits.
Death Leaper: This one is probably the weakest of the three, imo. His armor save is even worse, and even though he can deepstrike anywhere I kind of like the safety net of the standard Lictor's deepstriking rules. Then again, I'm not too experienced at the game at this point so I could be wrong.
Which one sounds like the most useful to go for?
You said they are from an older edition. Here are rules published for them after that codex was out of print. I think they are the same but I don't have my older codex handy (on a shelf somewhere). These rules can be used as if they are current.Warhammer 40,000 - Tyranids
The Red terror is the best of them. I have used it quite a few times in the past and it is very useful. It works by using it to harrass your opponent taking out vehicles that it can catch. Often it is best joining in an assault by other creatures when attacking infantry as this way it can avoid getting alot of hits. It's attacks can mess up Marines and so on quite well and it can make an attack by Spinegaunts change from annoying to threatening.
The ability to swallow whole is it's best feature as it is so much fun to eat people. This ability is obviously good for eating independent characters. Because it can pick it's target with this attack you can single out the guy with the powerfist and eat him if you want which will prevent him using it. Also if it happens to catch the last survivor of a squad getting to eat the victim whole for the sake of it is fun, a Guardman, Grot or Guardian (the more helpless/terrified the victim and the more it seems like unfair overkill the better).
You should eat lone models anyway, no matter how eak they are. There is no roll to wound when you swallow somebody, who knows all it's attacks might fail to wound if you're unlucky. Do beware though, the Red terror isn't very tough. I once lost it to an Eldar Ranger, it had lost all but one wound when they sniped it and it assaulted, one Ranger got a wound and it died.
Red terror is in my oppinion a great beast! His swallow whole is really anoying to your opponent. Have you ever tried to kill Eldrad al they while he just keeps protecting himself with his "reroll all saves" Psychic Power? That 3+ invul save is a pain in the ass. But let the Red Terror come in, and let him just litteraly eat Eldrad, and you're done!
The Old One Eye isn't really deadly to infantry, although most infantry on the other hand isn't realy deadly to the Old One Eye. However, he is quite usefull in keeping certain independent characters at bay, and is good at dealing with any tank he can get his claws in! Just make sure your opponet keeps pouring weapons fire at this guys, to make the most out of his Regeneration! Taunt your opponts if you have to or something
The special lictor, I think he's a bit off. I don't really see a reason to field him over any other option you have. I mean, a zoanthrope is almost the same amount of points, and more usefull.
can you actually uswe a red terror in tourney play
I think you should read the tournament regulations on that one. I think these 'official' special characters can be compared to Forgeworld models when looking for "is this model allowed". I think it all depends on the individual tournament regulations.
Go with the Red Terror. Just run up and eat the characters while assulting with 2 or 3 units, hopefully you'll survive the combat.
What are the stats of the Red Terror?
Red terror is one of my favorite looking models and has some cool fluff background.
9" Move and assault as well as 5 S6 attacks and the ability to remove a model from the board with no save? He is quite the beast, or perhaps quite the terror. Low initiative though.
Alright, so it sounds like the clear consensus is that The Red Terror is easily the best of the three. However, I am still intrigued by Old One Eye's regeneration ability, so I'm thinking of some way to incorperate him into my list as well. He would make quite the effective baitfex, right?
Old One Eye is indeed a great bait for getting a load of fire at him, IF he is intimidating enough to your opponent. Don't forget, people can still quite easily run away from this huge critter! And being a CC only fex, having to run across the battle field too find everyone running away from you means you are nothing more that a sheeps dog!
Try to find a central point for this guy, and try not to put him in a flank. Because when you put him in a flank, he'll probably be outrun, and the Old One Eye does nothing than walk/run around after he prey.
Another reason to but him in the centre, is make him litaraly the centre of attention! If all spotlights are on him, people will shoot him.
You can also use the Old One Eye as a bodyguard for your shooty fexes if you fear that they will be killed in CC. Although the Old One Eye isn't a great melee killer, he is very resilient! You can possible deal with 1 powerfist, because of average a powerfist will inflict 1 wound on the fex per combat round, meaning 2 wounds per turn. You regenerate 1 wound on your turn, so effectively, he's only dealing 1 wound per turn. Having 4 wounds and a high save, he can become a strong tarpit unit!
Also, the Old One Eye might be a great Dreadnought killer.
Another something to use his resilence for: put him on a objective at your opponent deployment side of the table. Your opponent will need a lot of effort to retake that objective!