Changeling

Changelings are shapeshifting fey beings. Most live in the Feywild, where they can be found among both the Seelie Court and the Unseelie Court. They are not native to Exandria, and they are rarely seen there. In their true or "at rest" form, they have pale skin, colorless eyes, and white hair.

The player characters Loquatius Seelie in Exandria Unlimited: Calamity and Dusk in Campaign 3 are changelings.

Appearance
In their true form, or their form "at rest", changelings have pale skin, colorless eyes that can be completely white or completely black, and white or silver-white hair. One individual is described as having dark shading around his eyes and very faintly visible black veins marbling across his skin that constantly but subtly move. Another individual is described as having dark eyes that "swirl with galaxies" and opalescent skin.

Loquatius Seelie demonstrated control over the visual effect of his shapeshifting. He was variously able to shapeshift as if paint was being drained out of his face and replaced with new colors and as if a film edit or cross-dissolve was taking place.

Abilities
As a playable race, changelings have the following abilities:
 * Shapechanger: Using an action they can change their appearance and voice at will, even adapting their size between small and medium. However, they can't assume the abilities of other races, neither take a form without the same basic arrangement of limbs they have.
 * Changeling Instincts: they gain proficiency with two of the following skills: Deception, Insight, Intimidation, Performance, or Persuasion.

As non-playable characters, they also gain access to:
 * Unsettling Visage: They can make someone frightened if said creature doesn't succeed on a Wisdom saving throw. Once a changeling uses this ability they can't use it again until they finish a long or short rest.

Note that for those changelings that are fey, instead of humanoids, some spells have no effect on them, since they target humanoids exclusively, while other spells will affect them precisely because of their fey nature.

History
Changelings are not native to Exandria, where they are "extremely rare" to see. The majority of changelings live in the Feywild.

At least one, Loquatius Seelie, lived in Avalir during the Age of Arcanum before The Calamity; he crossed into Exandria from the Feywild more than seven years prior. However, it is unclear if his identity as a changeling is widely known, even as he chooses to spend most of his time in his "at rest" appearance.

Changelings have belonged to both the Seelie Court and the Unseelie Court of the Feywild.

Notable changelings

 * Loquatius Seelie, a journalist in Avalir during the Age of Arcanum
 * "Dusk", an agent of the Seelie Court
 * Possibly a shapeshifting customer at the The Maiden's Wish casino

In The Legend of Vox Machina, which has a continuity separate from Critical Role, the Emonian tavern keeper seen in is a changeling. Their daughter is also possibly a changeling, but it is not clear.

Behind the scenes
Matthew Mercer initially he didn't considered changelings as one of the Exandrian races. However, when a poll was organized to choose the gender, race and design for a secondary character in The Legend of Vox Machina, changeling was one of the options. It was eventually chosen for said character. This meant that changelings became "accidentally" canon to Exandria. The Legend of Vox Machina is of a separate continuity from Critical Role, so changelings did not explicitly appear in the Critical Role canon until the introduction of Loquatius Seelie in Exandria Unlimited: Calamity.

Trivia

 * In folklore changelings were considered the fey babies left behind in the place of human children stolen by the faeries. Some variants of these legends were more general, considering changelings any substitutes for humans kidnapped by the fey.
 * Changelings were firstly featured as a playable race in Eberron: Rising from the Last War, although the term was also used in the Monster Manual to refer to the doppelganger offspring of a humanoid woman.