This is actually quite a long one, so it's gonna be unsurprising if this gets labelled as spam.

General:

Retreating - Run away on low health no matter what. If using a BOW type item, they will attempt to shoot the player whilst doing so.

Stalking - This behaviour has a 25% Chance to happen. If they see a target, they will initially run away as soon as you see it, whilst remaining out of sight. After 60 Seconds, they will start attacking the player.

Eating - If low on health, whilst Retreating, if far enough away they will eat any food in their inventory to regain health.

Sprinting - When the time calls for it, they will start sprinting, moving at 1.4x normal speed, and making all melee attacks knockback attacks.

Combat:

SWORD

Blades:

Basic Blade - When attacking, they will sweep attack their target.

Heavy Blade - When attacking, they are slower to attack than Basic Blade users but deal more damage.

Machete Blade - When attacking, if they encounter any grass they will sweep attack the grass itself, breaking all grass in a 3-block radius. Cannot sweep attack.

Short Blade - When attacking, they will swing faster than Basic Blade users, at the cost of dealing less damage.
Cannot sweep attack.

Throwing Blade - When attacking, if too far they will throw the weapon. Otherwise it functions as a Short Blade user. Cannot sweep attack.

Guards:

Wide Guard - Increases armor points of the Player Mob using the sword.

Sturdy Guard - Allows them to block attacks for 1.5 Seconds with a cooldown of 3 Seconds.

Forefinger Ring - Allows them to swing faster than usual.

BOW

Staves:

Long Stave - They would take longer to fire but they would deal more damage.

Recurve Stave - They would take shorter to fire but had less accuracy.

Straight Stave - Functions like a normal bow would.

Risers:

Extended Rest - Increases the amount of arrows they can fire.

Stabilizer - Increases the speed of fired projectiles.

Sights - Allow them to detect the player from further distances.

DOUBLE-HEADED

Heads:

Axe Head - Always deals critical hits.

Pickaxe Heads - Can mine through stone to reach the target. They can also see you through walls.

Claw Head - Can disable shields for a much shorter period than Axes can.

Adze Head - Deals nausea for much shorter periods than that of the Shovel. Can also disable shields for the same period as the Claw, but it only happens with a 33% Chance.

SINGLE-HEADED

Heads:

Shovel Head - Can deal Nausea for 5 + (Material Tier) seconds.

Spear Head - Does not deal Nausea, but deals the same damage as a Basic Blade.

Handles:

Basic Handle - Just your average tool handle.

Light Handle - Functions roughly the same as a Throwing Blade, but farther distances.

Long Handle - Increases range by 1.25x

SHIELD

Tower Plate - Constantly block until close enough to attack, but blocking will slow it down tremendously.

Heater Plate - Block for 3 Seconds with a cooldown of 3 Seconds, an upgrade from blocking with a Sturdy Guard.

Buckler Plate - Functions like a Wide Guard, but also gives a passive armor toughness bonus.

TRIMS:

Aerodynamic Trim - Functions the same as a Throwing Blade. Need I say more?

BOSSES:

Spiked Boss - Acts like thorns armor.

Miscellaneous Features:

Player mobs actively seek out and target other mobs, not just players.

If you can manage to increase the reputation to where they become your friend (They will spawn with 0 Reputation, the value for a neutral Player mob), they will allow you to access and modify their Inventory.

Reputation goes like this:

100 - The player mob is now your ally for all eternity. Only at this time can you modify and access their inventory.

50 - The player mob will not attack back, but attacking will lower the reputation by the amount of damage you deal to them

0 - Starting value. This is where they generally have a distrust for you, but will ignore you until you attack them.

-50 - They will start attacking you without warning.

-100 - They will sprint away until you can't find them anymore, and then they will team up with other Player Mobs to take you down.

All you have to do to increase their reputation is simply not attacking them. Every 2 seconds that you refuse to attack, their reputation goes up by 1 point. Giving them food by right-clicking them will increase the reputation by (hunger gain / 2) points.

this seems a bit complex, but nonetheless i like the reputation system