Kobolds seem to be a pretty popular choice of opponents for low-level/starting adventurers to face. These days, they seem to be pretty nasty. They are still physically weak, but highly organized masters of unconventional warfare and special weaponry.
Looking back at my old D&D and AD&D stuff, I really don't see much implication that kobolds are nasty, guerrilla fighters with an expertise in traps, bushwacking, and hideous treachery. By D&D 3.0, they are fortifying their lairs with traps, dumping flaming oil on people, tossing vermin at you, etc., etc.
I blame Tucker's Kobolds.
That editorial in Dragon was the first mention I can remember where kobolds equaled more than "something the fighter can kill at one per level per round."
I liked the idea of fodder-level opponents who used trickery and nastiness to attack people. I went ahead and used that idea so viciously in my GURPS 1e campaign that mentioning the name of the critters I used automatically invokes comments about their sneaky tactics. But I didn't use kobolds, I used derro. The derro from S4 The Lost Caverns of Tsojcanth already were pictured as using numbers and sneakiness to fight stronger foes. So I used them. It was fun, and it was even more fun watching the players turn the tide eventually with even more sneaky and ruthless tactics. As recently as my last GURPS campaign I used bushwacking cannibal pygmies (now immortalized as Horde Pygmies in DFM1), but they were more harassers than a real threat, and they weren't meant to do much more than whittle at the edges of the PCs . . . the vampire wizard and her tiger pet were the real challenge in that session.
Using kobolds still seemed a bit lame. They're just cruel egg-laying reptile-dog humanoids with wimpy damage and little combat power. I just can't get excited about them.
When I see them now, they're always using traps, poison, flamethrowers, unleashed hideous beasts, pits full of pungi stakes and grey ooze, whatever. They're always so freaking nasty you can't wait to be done with them. Just like Tucker's Kobolds. And my reaction is like what I imagined a lot of people's would have been - man, I get it, you can make fodder tough. Now can I go have fun fighting powerful monsters instead of sucking flaming oil every Saturday?
But to me, that was still a later development. So they still just seem . . . bleh. Boring. Lame. As fodder for 1st level old-school RPG games, they seem okay. But as commando killers, it's too derivative for me, and it feels forced. I'd rather make a somewhat more formidable race of evil trapmakers than feel compelled to make pure fodder into a tool for "GM Proving His Cleverness" games. Why not do it with more powerful foes - why aren't mind flayers and duergar and orcs and imps like this? They should be setting traps and being nasty commandos, not fighting you straight-up if you're tougher.
I don't seem to be in the majority. For example, the excellent Dungeon Alphabet made the "K" entry into Kobolds.
I don't want to rag on people who like this, I'm just saying . . . Killer Kobolds don't do it for me. I like nasty tactics, but I find sticking them on kobolds derivative and lame, because kobolds are boring and weak. Is it just me?