Shapeshifter, Doppelganger, Mimic, Changeling

Shapeshifter is a kind of generic term for several types of races that have the ability to morph their bodies into another form.  All of the races here could be considered shapeshifters.  However each one is slightly unique in their abilities.  Also each one of these is limited by the same rules of their race.

Doppelgangers
Doppelgangers are monstrous humanoids, infamous for their shapeshifting abilities that allow them to mimic almost any humanoid creature. They are lazy but cunning creatures, who kill or dispose of people then assume their place. While not downright evil, doppelgangers are extremely self-centered and liable to look down on their victims.  Doppelgangers are feared for their ability to assume the form of almost any humanoid creature they encounter. Doppelgangers are used as spies and assassins by many beings all over the world. Many doppelgangers live a stolen life. Should they encounter a person whose appearance or station they desire for themselves, the doppelganger will use their skills to learn everything they can about the chosen target. Once they have all the knowledge they need, they will quietly eliminate their target and assume his or her form, taking their place in life. They wear shapeshifter on the meter.

The other type of doppelgangers evolved from the union of humans and doppelgangers and are now a distinct race. While they are often called changelings they have a different background from the other changelings.  So to clear confusion, I will refer to these as either doppelgangers or hybrid-doppelgangers.  They have a limited ability to alter their forms, making them particularly suited to spying and criminal activity. Unlike pure doppelgangers, they have gender in their natural form, and while still having shapechanging ability.  These are the most common type of doppelgangers.
In their natural form, these mixed doppelgangers stand between five and six feet tall, with pale gray skin, thin, fair hair, and disproportionately long limbs compared to humans. Their facial features are more distinct than those of pure doppelgangers but less finished than those of humans; they have a hint of nose and lips, and blank white eyes. These kind are often used interchangeably with doppelgangers and thus wear shapeshifter on the meter.

Mimics
Mimics are strange aberrations that assume the form of mundane furnishings and household objects.  They maintain their forms for days at a time and lie in wait for unsuspecting prey to interact with them. Once the victim touches the mimic, the aberration springs to life, revealing a large mouth to quickly bite and consume its prey before it can escape. The mimic is aided by a chemical adhesive that is naturally exudes over its entire form.  Most mimics are the relative size of a human, assuming the form of small beds, chests, and wardrobes.  They wear shapeshifter on the meter.

Changelings
Changelings are a kind of Shapeshifter, and tend to maintain a humanoid form most of the time.
The Lore:  In ancient legends, a child stolen by the Fae from human or elven families would be replaced with a Changeling, who would trouble the family into which it was placed or the child stolen to faery would be considered a changeling.  True Changelings know their nature, but often keep their motives to themselves.
The Reality:  Imagine being kidnapped by the fae, used and distorted as a lesser in the land of faery.  You escape or are thrown away only to find yourself no longer human or elven but not fae either.  Time is different in faery and all your loved ones may be long dead though you feel you were only gone months or a couple of years.  You are Changeling. Changelings have adapted to being exposed to long-term faery magic very differently.  Their glamoury creates an actual bodily shift into another race.    They also tend to be pale in their natural form.

So that said:  Here are the rules on being one of these shapeshifters.  These applies to all the shapeshifters except mimics who can only shift into inanimate objects.

From the ROE:
Shapeshifter (Changeling)
Race of gaunt humanoids with the ability to take on the shape of any other living creature no more than twice their size or an eighth of their mass. (a changeling can not achieve a perfect imitation of another character. It will always be somewhat flawed.)

Shapeshifter (Mimic)
Race of amorphous gelatinous beings that take on the forms of Inanimate objects. They can change to any inanimate object to more than twice their size or one eighth of their mass

1.  Shapeshifters can shift into many other races.  However there must be a legitimate RP reason for the change.  Races you can shift into: Human, Ogre, Troll, Dwarf, Orc, Minotaur, Elf, Drow, Naga, Reptilian, Arthropod, Illithid, Gnome, Halfling, Faun, Nymph, Dryad, Merfolk, Siren, Insectiod, Goblin, Gargoyle, Avariel Elf, Valkyrie
2.  Shapeshifters can turn into animals and use beast claws in animal form.
3.  Keep your meter on shapeshifter/changeling regardless of race you shift to.
4.  There is no time limit to how long you can hold a shift.
5.  Shapeshifters can turn into flying races provided they are not magical/ethereal/spiritual fliers.
6.  Changelings can be considered Doppelgangers.


DON'TS
1.  Shapeshifters cannot shift into non corporeal races.  (No ghosts, elementals, spirits etc.)
2.  Shapeshifters cannot shift into undead races. (No vampires, lichs, zombies etc)
3.  Shapeshifters cannot shift into magical beasts. (No dragons, unicorns, gryphons, sphinx etc)
4.  Shapeshifters cannot shift into ethereal or spiritual beings (No fae, sprites, pixies, angels, demons)