Hands down , got to be my Coral Beauty- she beat to death 2 damsels and a domino, that were the 1st inhabitants in my Biocube 29. She still picks fights with my 2 clowns but they stand their ground usually retreating to their anemone. Bicolor Dottyback usually runs from her too, but also knows Shen to stand her ground.... Although last week I lost "Sebastian" my cleaner shrimp to my Sebae Nem who finally got a hold of him....;(