How do i make a Mob Watch the Player, but only moves its head

How do i make a Mob Watch the Player, turning only its Head and not the whole body, so it looks Player-like, and only rotates its body if the head reaches its limit on how far it can rotate

i know there are AITasks for it, but i want it so its doing it non-stop

Am trying to make a mod that adds stuff like Herobrine

So Far i have it so He stalks the player, and disappears if the Render distance is above 2 (by checking how many chunks are loaded around the player)

just need to work on the watching/staring but i don't know how to make it actually be player-like and not be obivous its a mob