Thanks so much for sharing this video. He's so very cute and entertaining!
Do you think it's the colours of the toy-fish that he's offended by? Maybe he's concerned that the hens will find the bright colours in the toy-fish more attractive than his own lovely feathers.
I don't have any hens (he's an "only child" ). Sometimes wild hens come in my yard, and I pick up my rooster and go take him out and put him near the hens, maybe 5 feet away, but he seems to have no interest in them.