Categories

Caption
A captioned image by Red Ochre (or someone else if specified) instead of a link to a story.
Magical Transformations
The character is transformed through magical means.

Chemical or Drug Induced Change
The character is transformed through the use of drugs.

Science Fiction
The character is transformed through methods common in science fiction, such as futuristic or alien technology.

Surgical Transformation
The character is transformed by undergoing sexual reassignment surgery.
Age Regression
The character becomes younger with the transformation.

Schoolgirl
The character attends school as a school-age female.

African
The character becomes someone of African ancestry (includes African American)

East Asian 
The character becomes someone of East Asian ancestry (Chinese, Korean, Japanese, Vietnamese, Laotian, Indonesian, etc)
European
The character becomes someone of European ancestry (commonly known as "white", includes white Americans, Australians, and so on)

Hispanic
The character becomes someone of Hispanic ancestry (any part of the Americas South of the Mexican-American border)

Indian
The character becomes someone of Indian ancestry (The Indian subcontinent, for American Indians, see Native American)
Middle Eastern
The character becomes someone of Middle Eastern ancestry (Arab, Jewish, Persian, etc)

Native American 
The character becomes someone of Native American ancestry.

Transnational Relocation
The character is relocated to a different country along with the change, generally their new ethnicity's country of origin (must involve a different country, not a different part of the same country)

Language Change
The character is transformed so they speak a different language other than their first one, generally the language commonly spoken by their new ethnicity, and often at the expense of their first language (acquiring the language must be a part of the transformation. Learning it normally afterwards doesn't count)

Religion Change
The character is transformed so they follow a different religion than their original one, generally the religion commonly followed by their new ethnicity (must be part of the transformation. Normal conversion doesn't count)