Answer:
Tashtego is the one who tells Captain Ahab the whale's name.
Step-by-step explanation:
In Herman Melville's MobyDick Tashtego, also described as Gay Head, is a Native American harpooneer who is part of the crew of Captain Ahab. After the singular whale was spotted by the crew, Tashtego told Ahab that the whale must be that one called "MobyDick", that is how Ahab discovers its name.