Doppelganger

The Doppelgangers cast no shadow and no reflection in a mirror or in water. They are supposed to provide advice to the person they shadow, but this advice could be misleading or malicious. They are a type of shapeshifter that mimics a particular person or species for some typically nefarious reason.

Doppelgangers are strange beings that are able to take on the shapes of those they encounter. In its natural form, the creature looks more or less humanoid, but slender and frail, with gangly limbs and half-formed features. The flesh is pale and hairless. Its large, bulging eyes are yellow with slitted pupils. A doppelganger’s appearance is deceiving even when it’s in its true form. A doppelganger is hardy, with a natural agility not in keeping with its frail appearance.

Doppelgangers make excellent use of their natural mimicry to stage ambushes, bait traps, and infiltrate humanoid society. Although not usually evil, they are interested only in themselves and regard all others as playthings to be manipulated and deceived.

It is natural form a doppelganger is about 5-1/2 feet tall and weighs about 150 pounds.

Source(s) 3.5E Monster Manual I, 3E Monster Manual I, Monstrous Compendium Volume 2, 1E Monster Manual 1, Basic Boxed Set, Rules Cyclopedia, Classic D&D Game, Monstrous Manual

Doppelganger
Medium monstrous humanoid (Shapechanger)
Hit Dice	4d8+4 (22 hp)
Initiative	+1
Speed	30 ft. (6 squares)
Armor Class	15 (+1 Dexterity, +4 natural), touch 11, flat-footed 14
Base Attack/Grapple	+4/+5
Attack	Slam +5 melee (1d6+1)
Full Attack	Slam +5 melee (1d6+1)
Space/Reach	5ft./5 ft.
Special Attacks	detect thoughts
Special Qualities	Change shape, immunity to sleep and charm effects
Saves	Fort +4, Ref +5, Will +6
Abilities	Strength 12, Dexterity 13, Constitution 12, Intelligence 13, Wisdom 14, Charisma 13
Skills	Bluff +10*, Diplomacy +3, Disguise +9* (+11 acting), Intimidate +3, Listen +6, Sense Motive +6, Spot +6
Feats	Dodge, Great Fortitude
Environment	Any
Organization	Solitary, pair, or gang (3-6)
Challenge Rating	3
Treasure	Double standard
Alignment	Usually neutral
Advancement	By character class
Level Adjustment	+4

Combat

When in its natural form, a doppelganger strikes with its powerful fists. In the shape of a warrior or some other armed person, it attacks with whatever weapon is appropriate. In such cases, it uses its detect thoughts ability to employ the same tactics and strategies as the person it is impersonating.

• Detect thoughts (Su) A doppelganger can continuously use detect thoughts as the spell (caster level 18th; Will DC 13 negates). It can suppress or resume this ability as a free action. The save DC is Charisma-based.
• Change Shape (Su) A doppelganger can assume the shape of any Small or Medium humanoid. In humanoid form, the doppelganger loses its natural attacks. A doppelganger can remain in its humanoid form until it chooses to assume a new one. A change in form cannot be dispelled, but a doppelganger reverts to its natural form when killed. A true seeing spell or ability reveals its natural form.
• Skills A doppelganger has a +4 racial bonus on Bluff and Disguise checks.

*When using its change shape ability, a doppelganger gets an additional +10 circumstance bonus on Disguise checks. If it can read an opponent’s mind, it gets a further +4 circumstance bonus on Bluff and Disguise checks.

Doppelgangers as Characters

Doppelganger characters possess the following racial traits.

• +2 Strength, +2, Dexterity,+2 Constitution, +2 Intelligence,+4 Wisdom, +2 Charisma.
• Medium size.
• A doppelganger’s base land speed is 30 feet.
• Darkvision Doppelgangers can see in the dark up to 60 feet.
• Racial Hit Dice A doppelganger begins with four levels of monstrous humanoid, which provide 4d8 Hit Dice, a base attack bonus of +4, and
  base saving throw bonuses of Fort +1, Ref +4, and Will +4.
• Racial Skills A doppelganger’s monstrous humanoid levels give it skill points equal to 7 x (2 + Intelligence modifier). Its class skills are Bluff, Diplomacy, Disguise, Intimidate, Listen, Sense Motive, and Spot.
• Racial Feats A doppelganger’s monstrous humanoid levels give it two feats.
• +4 natural armor bonus.
• +4 racial bonus on Bluff and Disguise checks. When using its change shape ability, a doppelganger gets an additional +10 circumstance bonus on Disguise checks. If it can read an opponent’s mind, it gets a further +4 circumstance bonus on Bluff and Disguise checks.
• Special Attacks (see above) detect thoughts.
• Special Qualities (see above) Change shape, immunity to sleep and charm effects.
• Automatic Languages Common.
• Bonus Languages Dwarven, Elven, Giant.
• Favored Class Rogue.
• Level adjustment +4.