@Foxhoarder has an explanation: What's a Hellgremlin? by:Foxhoarder
Now, these things are a spectrum but I think Lemonade has crossed over from being a brat to actual hellgremlin. I’m not including her reaction to the Alicorns yet as I think her killing her one baby would’ve happened regardless.
Their are people who enjoy hellgremlins, folks who hate them, and folks who are indifferent, but the tags help people sort stuff to find what they like 