so ive been thinking of the ways mobs behave in minecraft (animals not running away, zombies/skeletons chasing you into sunlight, ect.) for a while and have seen a few mods that implement the features i want but not standalone. so my proposal is as follows.
shoot webs at you
walk away from player when mob of different type is killed in line of sight or in same 3x3 chunk as them
run away from player when mob of same type is killed in line of sight or in same 3x3 chunk as them
tend to herd together with mobs of same type
try to use shade to prevent being burned in day but will chase player if within 6 blocks