A small child (is usually elementary school but is not limited to) or pet that exhibits mischievous and evil behavior to either purposely annoy someone or to match a goblin aesthetic
A mischievous, chaotic, wild, troublemaking, feral, unruly, and prankish person. The person may be reminiscent of a little moss-covered impish creature from the woods that is up to no good.
"I'm going tohave to bring my gremlin siblings to the party, I guess I'll have have to cross my fingers and hope they don't get in to much trouble"