@JeremyECrawford The Blood Hunter is listed as an additional class on D&D Beyond, under official classes, was it made official?
— Keith (@Glytched) January 30, 2018
The only official classes in D&D are in the Player's Handbook. For a new class to become official in the future, it must appear in a D&D book or must be announced as official by the D&D team. #DnD @DnDBeyond @Wizards_DnD https://t.co/2iRz4feoNV
— Jeremy Crawford (@JeremyECrawford) January 30, 2018
The Blood Hunter is actually categorized under 'Additional Classes' everywhere it appears in DDB. It is specifically not under 'Official Classes' and is not considered official.
— D&D Beyond (@DnDBeyond) January 30, 2018
— Matthew Mercer (@matthewmercer) January 31, 2018
You can download Blood Hunter class here: