"Beginning in a guest appearance in Fantastic Four #119 (Feb. 1972), the Black Panther briefly tried using the name Black Leopard to avoid connotations with the Party, but renaming did not last"

From Wikipedia and SHH:

When Fantastic Four member the Thing asked about the name change, T'Challa responded, "I contemplate a return to your country, Ben Grimm, where the latter term has —political connotations. I neither condemn nor condone those who have taken up the name, but T'Challa is a law unto himself. Hence, the new name—a minor point, at best, since the panther is a leopard."