It seems Martian Manhunter from the television adaptation of Superman's cousin "Supergirl," chooses to be an African American despite being able to shapeshift as anyone, as was explained by the character's actor, David Harewood.
Harewood stated that the powerful Martian Manhunter in "Supergirl" chose to be black because of how significant a message it can be to the viewers. Harewood expressed, "Here is a character that chooses to be black. He's a shapeshifter, he could be anybody, but he chooses to be black. And I think he chooses to be black, particularly in this day and age, because he understands injustice, he knows what injustice is about and as one of the most powerful people on the planet chooses to stand with those who are fighting injustice."
It can be recalled that Martian Manhunter was one of the staple members of the Justice League, particularly in the animated series, and he is actually one of the most powerful in the superhero collective, being comparable to Superman in terms of strength. Perhaps through the alien's observations of the human race, he has concluded that being black is one of the most shunned or discriminated qualities in humanity, which is why he chose to be one in order to experience what it means.
For fans of Martian Manhunter, particularly in the comics, the alien superhero has, on numerous occasions, assumed the form of a black man. He also did this in times of human rights crises, particularly in the 1960s during the upsurge in Civil Rights movements, as portrayed in the comics. However, this does not mean that the Martian has not taken any other forms and skin colors since there was one comic book arc where he assumed the form of an Asian female journalist.
This makes Harewood proud as a black actor, where the superhero he plays frequently assumes the form of the of the most oppressed races in human history.
