Chitines (pronounced like "Kite-ins" since their name is based off the word "chitin" which is what makes up insect exoskeleton) are an obscure race of humanoids from the ancient days of Dungeons & Dragons, who keep managing to creep on by through the slow tide of editions changing, despite almost nobody remembering them.
Chitines are small creatures who essentially resemble a blending of human and spider, rather like ettercaps or aranea in their hybrid form; though the precise details have changed from edition to edition, mostly in terms of how hairy they are, the basics always remain the same, presenting chitines as looking like humanoids with an extra pair of arms, an extra length & joint in each arm, multifaceted eyes, and horizontal mandibles growing out of their mouths. Dwelling in dark places like the Underdark or really creepy and overgrown forests, Chitines live simple lives of hunting and prayer; they are devout worshippers of Lolth, dedicated to earning her favor, and needless to say this doesn't make them good company. About the nicest thing that you can say for chitines is that they absolutely detest the Drow, and constantly strive to hunt and kill them in hopes of usurping their place as Lolth's favored children. Naturally, the drow don't approve of this.
The irony of it is that chitines are generally portrayed as being drow creations; the result of experiments at blending humanoid (or elf, in 5e) slaves with spiders to create a superior workforce, which of course went tits up on them. Exactly why this is the case was left undiscussed until 5th edition, when it was stated that despite invoking Lolth's divine power to keep the original creatures alive instead of collapsing into a puddle of goo the drow never ceremonially dedicated the resultant creatures to her. The fickle and insane goddess didn't appreciate being used as a mere power source (although to be fair, no god in the D&D-verse would) so she punished the Drow for this outrage by subtly arranging for the Chitines to rebel.
This rebellion was fostered by the Choldriths, an entirely separate species of mutant female chitines. With an instinctive connection to Lolth's power, giving them the spellcasting abilities of a 4th level cleric, these are the sacred leaders of the Chitine tribes, inspiring them with sermons about how they are Lolth's chosen people and driving them to glory in the Spider-Queen's name. Choldriths have changed a lot over the editions: when they first appeared in the Ecology of the Chitine (Dragon Magazine #223), they were described as resembling unusually large female Chitines with completely hairless bodies, dark gray skin, non-faceted eyes, and elf-like ears so long that they resemble horns. When they reappeared in 3rd edition (Monsters of Faerun), they were depicted as giant albino spiders with the head of a mandibled, faceted-eyed female elf and its front two limbs mutated into humanoid arms, although it retained the oversized/horn-like ears of the previous edition. 4th edition described them as resembling "pale-skinned driders" in the Monster Manual 3. 5th edition returned to the 3e appearance, only with a more hideously spider-like face, and now colored gray instead of white.
Likewise, the status of Choldriths has changed between editions; from sterile mutant priestesses in 2nd and 3rd edition, 5th edition changed them into the "queens" of the Chitine race; regular Chitines are worker & warrior drones, sexless and incapable of breeding, whilst the female Choldriths produce all of the eggs that support a tribal-colony, rather like ant-queens. In earlier editions, chitines were a fairly normal tribal culture - albeit with a really rough coming of age ceremony.
Ironically, despite worshipping Lolth and thusly having a predominant alignment of Chaotic Evil, chitines actually do have a fairly pronounced number of outliers and are fully valid for PC writeups, at least in Advanced Dungeons & Dragons 2nd edition and Dungeons & Dragons 3rd Edition. Why? Well, partly it's because the drow hate Chitines and tend to exterminate them, leading to lone survivors joining up with adventuring parties in the Underdark for survival and/or revenge. Another reason, at least in 2nd edition, is because many curious Chitines seek to find the true circumstances behind the drow experiment that created them. Others are just eager to tag along with powerful adventurers who're out to crack some drow skulls, as that's a goal they can eagerly cooperate on. And many are simply heretics who've realised that Lolth is a bitch who doesn't deserve worship, which gets them cast out as heretics and so find themselves in desperate need of a new people to belong to.
The Chitine's obscurity is cemented in that, despite being humanoids, they didn't actually get an official writeup in the Complete Book of Humanoids, despite the abundance of other races who did so; aarakocra, alaghi, beastmen, bugbears, bullywugs, centaurs, fremlins, firbolgs, voadkyn, gnolls, goblins, hobgoblins, kobolds, lizardfolk, minotaurs, mongrelmen, ogres (pureblood, half-ogre and ogre mage), orcs (pure and half-orcs), pixies, satyrs, saurials, swanmays and wemics. No, chitines appeared in Dragon Magazine #262, where they had the following writeup:
- Ability Score Adjustments: +1 Dexterity, +1 Constitution, -2 Charisma
- Ability Score Range: Strength 6-6-18, Dexterity 8-19, Constitution 7-19, Intelligence 8-18, Wisdom 6-18, Charisma 3-16
- Class Restrictions: level 12 Fighter with the Tribal Defender, Mine Rowdy, Pit Fighter and Sell Sword kits, level 15 Thief with the Scavenger, Tunnel Rat and Shadow kits, multiclassed Fighter/Thief
- Natural Armor Class: 9
- Base Movement Rate: 9 on webs, 12 elsewhere
- Special Advantages:
- Can move on walls and ceilings via climbing.
- Base Climb Chance of 120% before adjustments are applied.
- Nullifying oils means that a chitine cannot be entangled in its own webbing. When making a save to avoid being entangled in webbing from other sources, it automatically passes the save. If the webbing would not normally allow a save, the chitine can still avoid entanglement by passing a save vs. paralysis with a +4 bonus.
- Chitines can spin 1 foot of webbing per round. Chitine webbing can be solidified, allowing it to be used as raw materials for proficiency checks marked with an *. It also means that they can avoid taking damage from hard falls.
- Chitines can wield weapons in all four of their arms. They can use up to three weapons simultaneously with no penalty, and can carry a shield in their fourth hand without a penalty. If they wield weapons with all four arms, they suffer a -1 penalty to all attack rolls.
- Special Disadvantages: Chitines suffer a -1 penalty to attack & damage rolls when in bright light.
- Weapon Proficiencies: Javelin, Shortsword, Dagger, Knife
- Non-Weapon Proficiencies: Alertness, Appraising, Armorer*, Artistic Ability, Blacksmithing*, Carpentry*, Close-Quarter Fighting, Danger Sense, Direction Sense, Fast-Talking, Fishing, Fortune Telling, Gaming, Hiding, Hunting, Juggling, Jumping, Local History, Looting, Mining, Observation, Rope Use, Seamstress/Tailor, Set Snares, Stonemasonry*, Tightrope Walking, Tumbling, Weaponsmithing*, Weaving*
- Thieving Skill Adjustments: Pick Pockets -5%, Open Locks -5%, Find/Remove Traps +10%, Detect Noise +5%, Climb Walls +80%
Third Edition was a bit of a better show for Chitines, as they managed to make it into not one, but two official sourcebooks instead of Dragon Magazine. First appearing in the Monsters of Faerun splat, where they had the same "play a monster" rules as just about any monstrous critter, they received a proper PC write up in the Underdark sourcebook, which made them look like this for 3.5:
- Ability Score Modifier: +2 Dexterity, +2 Constitution, +2 Intelligence, -4 Charisma.
- Size: Small
- Base land speed: 30 feet
- Spidery Climber: Chitines have a Climb speed of 20 feet, a +8 racial bonus to Climb checks, can always take 10 on Climb checks, and can clamber up walls and across ceilings as if under a permanent non-magical Spider Climb spell.
- Grappling Bonus (Ex): +4 bonus on grapple checks.
- Difficult to Disarm (Ex): +4 bonus to opposed checks to resist being disarmed.
- Sunlight Sensitivity (Ex): Chitines are Dazzled in sunlight or equivalent levels of bright magical light.
- Racial Hit Dice: A chitine begins with two levels in "Monstrous Humanoid", which gives it 2d8 Hit Dice, BAB +2, Fort +0, Ref +3, Will +3.
- Racial Skills: A chitine begins with 5 X (2 + Int modifier) skill points and treats Balance, Climb, Craft (Trapmaking), Hide, Jump and Move Silently as class skills.
- Racial Feats: Multiweapon Fighting and one bonus feat.
- Weapon Familiarity: Chitines treat Shortswords as being Simple Weapons rather than Martial Weapons.
- Chitine Web Implements: Chitines use their webbing as a construction material for homes, traps, and armor. They can harden their webbing to create spikes and edges in their traps, and each such sharp feature typically deals 1d6 points of damage. Weapons, armor, and other objects made from hardened webbing deteriorate after several months if not regularly treated with the oil secreted by chitines' skin. Items made of chitine webbing are also susceptible to fire - 2 rounds of contact with flame ignites such an item, burning it away in 2d4 rounds.
- Favored Class: Rogue
- Level Adjustment: +2