Appears to be re-vegging pretty hard, time to check all your timers etc. Nothing to do with fox tailing at all, you would need actual flowers to have fox tailing.
foxtailing is where the flowers start produceing independant flower heads and start pokeing out all over the place. it usualy happens with a high sativa cointent plant or a pure sativa. just like in the pic. so its not thatView attachment 5266715
I've seen it happen to indicas if the heat is too high or they are suffering from light stress. I find going over 800 ppfd with LEDs start to stress them out. I think what they have is either a hermie or a male.