Yes, Nikabrik was a black elf. Black elves, also known as dark elves, are a race of elves that have darker skin tones than the traditional fair-skinned elves. They are often depicted as being associated with dark magic, being more aggressive, and having a more tribal culture than other types of elves. In the Narnia books, Nikabrik was one of the characters who belonged to this group, and he was known for his resentment towards the High King Peter and his friends, as well as his loyalty to the White Witch.