When I create Snow Golems, and they start firing Snowballs at, say, Zombies, they do not look at the target, but look elsewhere, such as at the Player (if it is nearby). Sometimes they appear to realise that a mob is there and stare at it.
To replecate this:
1) Create a Snow Golem.
2) Spawn a hostile mob that Snow Golems shoot at.
3) Stand near the Golem, and it will look at you or somewhere else, whilst throwing Snowballs at the mob.
This looks ridiculous and false and I like how mobs look at one another when fighting.