From BRWiki

D20

This article is a D20 reference page The System Reference Document is a comprehensive toolbox consisting of rules, races, classes, feats, skills, various systems, spells, magic items, and monsters compatible with the d20 System version of Dungeons & Dragons and various other roleplaying games from Wizards of the Coast.

D20

SNAKE, SMALL VIPER

These creatures range widely in size. They are not particularly aggressive, but will often lash out with a bite attack before attempting to retreat.

Skills: Snakes have a +4 racial bonus on Hide, Listen, and Spot checks and a +8 racial bonus on Balance and Climb checks. A snake can always choose to take 10 on a Climb check, even if rushed or threatened. Snakes use either their Strength modifier or Dexterity modifier for Climb checks, whichever is higher. A snake has a +8 racial bonus on any Swim check to perform some special action or avoid a hazard. It can always choose to take 10 on a Swim check, even if distracted or endangered. It can use the run action while swimming, provided it swims in a straight line.

COMBAT

Viper snakes rely on their venomous bite to kill prey and defend themselves.

Poison (Ex): A viper snake has a poisonous bite that deals initial and secondary damage of 1d6 Con. The save DC varies by the snake’s size, as shown on the table below. The save DCs are Consitution-based.

SEE WIKIPEDIA ENTRY: Snake

System Reference Document -> List of Creatures (SRD)