The product of a dark and terrible ritual.

Pregnant Goblin females blood is drained by specially bred vampire bats, who are then in turn slain and their blood is made into a ritualistic drink by the goblin shamans, which is given back to the pregnant goblins to drink.

This process repeats several times. Most of the females do not survive the process, but those who do, give birth to a Goblat! Combining the "best" qualities of Goblins and Vampire bats.