Goblins

Goblins are monsters that are mentioned in monster high. A goblin is a monstrous creature from European folklore, first attested in stories from the Middle Ages. They are ascribed various and conflicting abilities, temperaments and appearances depending on the story and country of origin.

Monster High
In monster high there is only mentions of goblins as there was never a goblin character that was named before.

But in monster high goblin's have their own language, called Goblinese.(Or it's a pun name for Japanese)

In monster high there is a character named Herbert East, it's possible he's a goblin but nothing has been confirmed.

In Hexiciah Steam's SDCCI diary, there is mention of a goblin but not much is known about the goblin that was mentioned only that the goblin was playing cards with Hexiciah Steam and a werewolf.

Discription
It's unknown what goblins look like exactly, if Herbert East is a goblin then goblin's in monster high have green skin, and pointy ears.

Etymology
Middle English: from Old French gobelin, possibly related to German Kobold (see kobold) or to Greek kobalos ‘mischievous goblin’. In medieval Latin Gobelinus occurs as the name of a mischievous spirit, said to haunt Évreux in northern France in the 12th century.