Goblins

While Mrs. Rowling does not seem to envision any real differences that I am aware of, other sources would give us different kinds of goblins that have distinct properties. I am unsure how to entirely mesh this with what we find in the books.

One thing of note, that I found in reading other people's ideas on this series.

Hagrid, who has a pet Cerberus named Fluffy, who describes Dragons as cuddly, and thought Aragog of all monstrosities was harmless, referred to Goblins as

"They're goblins, Harry. Clever as they come goblins but not the most friendly of beasts. Best stay close"

Meaning Hagrid, the Acromantula Rancher, the Dragon Cuddler, the guy who named a Cerberus Fluffy and does illegal "Harmless" crossbreeding, thought Goblins were dangerous.¹

What does it take for Hagrid of all people to classify a race as dangerous?