D&Dtools1

This spell causes the target to assume some of the qualities of the yuan-ti tainted one template, which provides several benefits.
First, the target gains the Alertness feat.
Second, the target's Constitution score increases by 2.
Third, the target becomes completely immune to snake venom and yuan-ti poison.
The target assumes a more feral and snakelike appearance (slitted pupils, elongated teeth, and so on) and is considered a yuan-ti for the purposes of all spells and effects (such as being subject to a ranger's favored enemy bonus against yuan-ti, not being able to form a ghost if slain, and so on).
This spell was created by the yuan-ti to temporarily bolster their ranks with followers in a short period of time.
Most other clerics would never consider casting this spell.
The spell is normally used on willing victims, since it grants the caster no control over the target.
Material Component: A few drops of the mixture that yuan-ti use to create tainted ones, which the target of the spell must swallow.