The novel was filmed in the USA - 1930 (Captain Ahab - D. Barrymore) and 1956 (in the same role - G. Peck).
ANSWERS ON QWESTION:
Who or what is Moby Dick?
"Moby Dick" is a white whale in which the main character of the novel wants to take revenge. After Ahab loses his leg, a great war breaks out between them. However, the image of the White Whale is far from unambiguous. Sometimes it really acts as a capacious symbol of the blind cruelty of nature, but sometimes it can be perceived as an allegory of the harsh Old Testament Almighty, punishing human pride and villainy. And yet, for all the semantic ambiguity of the images of the novel, the reader does not leave the feeling of the author's deep sympathy for the Promethean sacrificial stubbornness of Ahab. For Stubb, Moby Dick is just a whale. A huge white whale, and nothing more. For Ahab, Moby Dick is the embodiment of all the Evil in the world.
For Ishmael, it is a symbolic designation of the universe. And the point here is not that Moby Dick is symbolically represented in several guises. The point is in the type of cognizing consciousness.