Word Of Changing

Warlock Invocation
Level: Dark, 5th
Components: V, S
Casting Time: 1 standard action
Range: Close (25 ft. + 5 ft./2 levels)
Duration: Permanent
Saving Throw: Fort negates, Will partial(See text)
Spell Resistance: Yes

You utter a powerful word that transforms a creature into an inoffensive form. This effect functions like the baleful polymorph spell, except that 24 hours after being transformed, the subject is entitled to a second saving throw (at its original save bonus) to spontaneously resume its normal form.
If this second save fails, it remains in its new form permanently or until restored by some other means.

Baleful Polymorph:

You force the subject to assume the form of a Small or smaller animal of no more than 1 HD. The subject takes on all the statistics and special abilities of an average member of the assumed form in place of its own except as follows.

The target retains its alignment and personality, within the limits of the assumed form’s ability scores.
If the target has the shapechanger subtype, it retains that subtype.
The target retains its hit points.
The target is treated as having its normal Hit Dice for purpose of adjudicating effects based on HD, such as the sleep spell, though it uses the assumed form’s base attack bonus, base save bonuses, and all other statistics derived from Hit Dice.
The target retains the ability to understand but not to speak the languages it understood in its natural form. It can write in the languages it understands only if the assumed form is capable of writing in some manner, such as drawing in the dirt with a paw.

With those exceptions, the game statistics of the assumed form replace the target’s normal ones. The target loses all the special abilities it has in its natural form, including its class features.

All items worn or carried by the subject fall to the ground in the subject’s space, even if they could be worn or carried by the assumed form.

If the assumed form would prove fatal to the creature— such as if you polymorphed a landbound target into a fish, or an airborne target into a toad—the subject gets a +4 bonus on the save.

If the subject remains in the assumed form for 24 consecutive hours, it must attempt a Will save. If this save fails, the subject loses its ability to understand language, as well as all other memories of its previous form, and its Hit Dice and hit points change to match an average creature of its assumed form. These abilities and statistics return to normal if the effect is later ended.

Incorporeal or gaseous creatures are immune to baleful polymorph. A creature of the shapechanger subtype can revert to its natural form as a standard action, ending the spell’s effect.

(Complete Arcane, Page 134)