Master of Many Forms

Master of Many Forms is a prestige class in version 3.5 of Dungeons & Dragons that acts to extend the Druid's wild shape feature as far as possible. Transforming the wild shape feature into a full fledged shapeshifting ability, the improved wild shape ability granted by the class allows changing into other humanoid forms at first, and at higher levels allows additional forms such as Fey, Dragon, Ooze, Vermin, and Aberration, at the rate of one new creature type per level. In addition, every other level a new size is available for changing into. Some of these sizes and creature types are unique to the Master of Many Forms, either not being available in the regular wild shape of the Druid, or requiring feats to be able to do.

Level	1	2	3	4	5	6	7	8	9	10
Shape	Humanoid	Giant	Monstrous Humanoid	Fey	Vermin	Aberration	Plant	Ooze	Elemental	Dragon
Size		Large		Tiny		Huge		Diminutive		Gargantuan

One of its level one abilities allows for not only speaking normally with other creatures of the same kind, but also the ability to speak normally in wild shape forms as if you were not transformed, allowing for talking animals, oozes, and such. You can't do the latter with wild shape regularly, even as a parrot, due to a clause that requires you to make only sounds of an untrained animal, and it also declares speech as a trained only ability.

In addition to a 3/4 BAB and good Fort and Ref saves, the prestige class grants a few other options as well. A third level Wild Shape becomes a move action rather than a standard action, at level 7 you get all the Extraordinary abilities the creature has (often including at-will powers), and at level 10 you get Shapechanger as a subtype. In addition to all of this, the Master of Many Forms also gets one additional use of Wild Shape per level, meaning a total of 16 uses at level 20, or 19 with Totem Druid.

Like other prestige classes this class is expected to be entered at level six, possibly after five levels of Druid and gaining wild shape, but its simple requirements of getting the Endurance and Alertness feats along with wild shape allow for gaining it at level two due to the Totem Druid getting wild shape at level one, or with the Divine Minion template at level 3 (because of the +1 LA). It can also be reached with the wildshape variant Ranger at level 6, which is preferred due to the lack of spellcasting improvement in the prestige class.

The obvious use to this is that the Master of Many Forms has a tremendous variety of creatures to choose from, not just those formally restricted by type but also by size. Turning into a T. rex and devouring dudes or a Roc and ferrying around your party has a lot of potential, but can leave a player overwhelmed with all the options. The best practice is to make a shopping list in advance so you have on hand what you can turn into.

The problem with this class is the same that the normal Druid has: the Familiarity Question. Some DMs demand that you have seen a creature before you can turn into it. While this is not a problem to some DMs, others will not allow you to shapechange into them because of reasons. The best piece of advice for this is talk with your DM about this before you play a Master of Many Forms, and don't be a dick and try to break the DM's game by turning yourself into Pun-Pun.

Shifter class

The Master of Many Forms is an updated version of the Shifter prestige class from third edition - not to be confused with the Shifter race introduced with Ebberon, which while having a sort of shape changing mechanic, doesn't come close to the power or mechanics of either class by itself. Notable elements that the Shifter class has over the Master of Many Forms include more creature types to turn into, including animals (possibly overriding any limits on animal changing you may have from your class), outsiders (so you can theoretically turn into an achaierai), and even constructs, gaining dark vision at level 10, and gaining unlimited regular wild shapes - and thus greater wild shape - at level 10. It seems as if Wizards of the Coast thought the Shifter was too overpowered or something and put a nerf on its capabilities.

Another notable element is that this prestige class has appeared in an expansion for the 2002 Neverwinter Nights game, in a modified form with more restricted form selection, but the Master of Many Forms class (its v3.5 version) didn't appear in Neverwinter Nights 2, neither in the original game or official expansions.

Other editions

So far there has not been an equivalent class in future editions of Dungeons & Dragons. The one that comes closes in fifth edition is the Druid's Circle of the Moon subclass, but it doesn't come close, still being restricted to beasts and elementals, and not having an inherent ability to speak normally in these forms.