What's the rarest Megalodon in Sea of Thieves?

Could you please clarify what you mean by "rarest Megalodon" in the context of Sea of Thieves? Are you referring to a specific type of Megalodon shark encounter that is particularly rare within the game? Or perhaps you're asking about a unique Megalodon-related item or achievement that players may find challenging to acquire? If you could elaborate on your question, I'd be happy to provide a more detailed answer tailored to your inquiry.