Ophidian (CR 2)

Medium Monstrous Humanoid (Reptilian)
Alignment: Usually chaotic neutral
Initiative: +2 (Dex); Senses: darkvision 60 ft., Listen +3, and Spot +3

AC: 17 (+2 Dex, +2 large wooden shield, +3 natural), touch 12, flat-footed 15
Hit Dice: 3d8 (13 hp)
Fort +1, Ref +5, Will +3
Speed: 20 ft., climb 15 ft., swim 50 ft.
Space: 5 ft./5 ft.
Base Attack +3; Grapple +4
Attack: Scimitar +4 melee, or bite +4 melee
Full Attack: Scimitar +4 melee, or bite +4 melee and scimitar -1 melee, or scimitar +4 melee and bite -1 melee
Damage: Scimitar 1d6+1 (1d6 as secondary attack); bite 1d4+1 (1d4 as secondary attack)
Special Attacks/Actions: Serpentine curse
Abilities: Str 12, Dex 15, Con 11, Int 8, Wis 11, Cha 10
Special Qualities:
Feats: Alertness; Dodge
Skills: Climb +9, Hide +3*, Listen +3, Move Silently +3, Spot +3, and Swim +10
Advancement: 4-5 HD (Medium-size); 6-9 HD (Large)
Climate/Terrain: Warm forest and underground
Organization: Solitary or clan (3-12)
Treasure/Possessions: Standard

Source: Fiend Folio

Ophidians are not bright, but they often fight under the leadership of more intelligent creatures (such as nagas or yuan-ti). They make good use of their natural camouflage to attack with surprise, though their distaste for ranged weapons makes that advantage less effective than it might otherwise be. They can wield weapons comfortably in their humanoid hands, but nevertheless ophidians love to bite their victims, and they particularly delight in infecting opponents with their serpentine curse. If it desires, an ophidian can make its bite attack its primary attack and use a weapon for its secondary attack.

Serpentine Curse (Su): Any humanoid bit by an ophidian's bite attack must succeed on a Fortitude save (DC 11) or contract a curse that will turn the victim into an ophidian. Starting 1d4+1 days after infection, the victim slowly becomes more snakelike: Its skin grows scaly, its legs begin to shrink and fuse together, and its tongue becomes forked. After two weeks, the victim is fully transformed into an ophidian, with no memory of its previous existence. To stop the transformation, the victim must receive a remove disease or remove curse spell before the process is complete, although these spells do not undo any transformation that has already begun. A heal, regeneration, limited wish, wish, or miracle spell is required to reverse the transformation. Once the transformation is complete, nothing short of a wish or miracle can return the victim to its previous state

Skills: Ophidians have a +8 racial bonus on Climb checks and can always choose to take 10 on Climb checks, even if rushed or threatened. Ophidians have a +8 racial bonus on any Swim check to perform some special action or avoid a hazard and can always choose to take 10 on Swim checks, even if distracted or endangered. *Ophidians also have a +10 bonus on Hide checks in forests or underground areas due to their chameleonlike ability to alter their skin tones.

Reptilian Subtype

These creatures are scaly and usually cold-blooded. The reptilian subtype is only used to describe a set of humanoid races, not all animals and monsters that are truly reptiles.