Heya.
My son is 4. He has a speech delay and has been assessed for autism a couple of times, though it has come back negative with them electing to still monitor it. Most of the time he's pretty well behaved but recently he has become unreasonable when he does not get his way.
For example; we are in the garden and for the most part he's behaving himself. He then starts to throw something in the pond and I tell him to stop. He, obviously hearing me, decides to do it anyway. I tell him it's time out and he just responds "no", folds his arms and walks away from me. I eventually get hold of him and sit him on the stairs and thats when he starts grunting/growling/shouting very loud; tensing his whole body, fist clenched etc. as he does.
And this behaviour is becoming very typical. He refuses an order, we have to physically drag him to the stairs (or husband lets off his Mufasa shout) then he continues to shout/scream (he also will tense one side of his face; left eye closed, left side of the mouth opened, and left side of his teeth clenched. Sign of something?).
It's actually getting quite distressing.