COMPLETELY unnattached to life.

[Enkhidu]

I've always got a half dozen campaign/background ideas floating around, and one of them I had was to do some quick renaming to give the game a more Anglo-Saxon feel. I renamed D&D ogres as 'trolls', and then took the basic D&D troll, removed the fire vulnerability and renamed it a 'black troll.' Black trolls were utterly fearless, unstoppable killing machines, and hardened soldiers needed to go and change their armor even at the thought of fighting them. (Supposedly, they were 'Trolls' that were burned in the fires of Hell and proved evil and viscious enough that they survived it - their skin was ever after charred).

So, depending on exactly how nasty you want these things, you might go with that.

 

[Ourph]

Fiendish Dire Lemmings.

 

[Lasher Dragon]

Fiendish Dire Lemmings.

Dude that is awesome LMAO

 

[Mercule]

Any humanoids that are weak individually, but have good group tactics. Kobolds and goblins fit, just remove their stereotypical cowardice. Why do they pile on? Because they've seen it work. Why the crazy stunts and seemingly suicidal behavior? Because their society promotes the whole over the parts. Why are they fearless?
Because they're fatalists. No fanatacism, no insane religious berserkery. Just the calm, certain knowledge that their fate is pre-ordained, and they can't do anything to stop it. Make it cultural, not just religious. What did the guy say in 13th Warrior? "The All-Father wove the skein of your life long ago...Fear profits a man nothing."

Viking lemming kobolds. I love it! Sounds like the personality bump I've been looking for.

 

[Crothian]

Fiendish Dire Lemmings.

that's beyond awsome.....

 

[Gothmog]

I did something like this in my campaign once, but it wasn't a race, but instead a drug/herb people ingested that turned them into weak-willed homocidal maniacs with no self-preservation instincts. The infernally-tainted herb was cultivated by a sect of diabolists in service of Mammon, and introduced into food via a particular inn. The diabolists ran the inn, and then watched patrons who seemed to be susceptible to the drug, offering them a "free room" for the night. Once in the free lodgings, the diabolists planted suggestions into the target, and sent them on missions. Once the drug wore off in about 6 hours, the victim remembered nothing, and if victim carried out his mission, he'd go back to the inn and wake up remembering nothing. If he was caught and interrogated, he'd act like a maniac for a while, then snap out of it- this would be labeled demon possession by the authorities, and the target would be executed for witchcraft. It took the PCs a long time to figure it out, but eventually they did by making one of themselves the "mark" for the drug.

 

[Kyrail]

I gotta vote for Gibberlings too.

 

[The_Universe]

Skaven (ratmen) are a good choice-- life is cheap in a litter of 30.

I think this is key to having them make sense as a widespread race. Only a race with little biological imperitive to preserve themselves are going to act like this in any truly large numbers.

You can have fanatics of any race and creed that might do so, but they'll be relatively small in number. That's why there aren't armies of millions of suicide bombers in the real world - just a (relative) few fanatics willing to go that far.

Maybe make them like ratmen/skaven, but have the vast majority of the race be males...only a few need to survive to mate with females who produce enormous litters on a nearly continuous basis.

Insectoid races can work like this, as well - and bugs freak people out even more consistently than rats do.

 

[Kid Charlemagne]

Use something that is Astrally Projected to this world. When you die while using Astral Projection, you don't die, your spirit just returns to its original body. You can sacrifice yourself, and then do it again tomorrow, with absolutely no regard for your own safety. That could be the really freaky part - the suicide fighters don't even seem worked up about it. Works great for Mind Flayers and their minions.

 

[Henry]

Use something that is Astrally Projected to this world. When you die while using Astral Projection, you don't die, your spirit just returns to its original body. You can sacrifice yourself, and then do it again tomorrow, with absolutely no regard for your own safety. That could be the really freaky part - the suicide fighters don't even seem worked up about it. Works great for Mind Flayers and their minions.

This may sound weird, but.. what about formians, or an insectile race? When you reproduce not just in the dozens, but in the THOUSANDS, and your life is pheromone driven, you will do some crazy stuff in defense of the colony.