I've added a few... obviously some are for heroes only.
Assassin: Requires Stealth and allows the ability for the unit to engage with a random commander of an area and the commanders personal guards.
Resistances: Fire/Water/Air/Poison/Life/Death... depending on the unit each of these resistances may vary from -200% to 300%. I write 300% because within another TBS game certain buffing spells reduced resistances as a side effect causing a fire elemental to go burning once buffed... thus a fire elemental at 250% would never set himself on fire even after being buffed.
Auras: Chill/Heat/Darkness/Awe/Plague/Fear/Poison/Light/Courage... depending on the level each provides a possible negative effect to enemy units and possible positive effect for friendly units. Description for each available upon request.
Recouperation: Unit heals permanent battle wounds over time... such as having lost one eye.
Night Vision: Unit is able to see in darkness without any penalty.
Flying: Unit is able to fly over the majority of land obstacles, yet one of its movement squares must be a land square each turn. This prevents a tiny bird from being able to fly across an enormous ocean without need for resting.
Self-Sustaining: Unit does not need to eat food.
Animal/Undead/Demon/Angel/Magical: Unit can be affected by spells specific for whatever types match.
Cold Blooded: Unit is cold blooded and can be affected by spells specific for cold blooded units. Also more likely to suffer penalties in cold terrain.
Regeneration: Unit regenerates hitpoints during battle ranging from -50% to 200%. This is to help cover any buffing spells which may have a negative side effect... naturally a unit can only use up to 100% of regeneration.
Trampling: Unit will trample across enemy units while moving on the battlefield. When unit is fleeing the unit may trample over friendly units while trying to preserve its own life.
Amphibian: Unit is able to travel and breathe underwater with no penalties. *Important once we can have battles underwater.*
Petrify: Whenever the unit looks at anyone it may cause the target to turn to stone. (Medusa effect).
Ethereal: Only 30% of normal weapons strikes are able to harm this unit. (Linked to units such as ghosts)
Immortal: Once the unit is killed by a normal weapon it respawns at the capital of its master. (Linked to units such as powerful vampires)
Lifeless: Units which have been animated from non-living resources such as golems. These units are immune to life stealing, sleep, petrify and morale.
Aquatic: Units are only allowed to travel on water type terrains.
Lavatic: Units are only allowed to travel on lava type terrains.
Burrowers: Units can travel through the earth and dirt.
Fortune Teller: This unit increases the chances for a good event at its location.
Psychic: This unit decreases the chances for a bad event at its location.
Mindless: This unit has no mind and unaffected by spells which attempt mind control or mind damage.
Limited Life: This unit never regains hitpoints lost during battle or map movement.
Ambidextrous: This unit is able to use both hands equally well... thus no penalty for using two one-handed weapons.
Amquadextrous: This unit is able to use all four hands equally well... thus no penalty for using four one-handed weapons.
Dragon Slaying: This unit receives bonuses while fighting dragon type creatures.
First Strike: This unit is usually able to strike first when next to an enemy.
Wall Crushing: This unit is able to damage walls as well as buildings.
Knockback: This unit when striking might cause it's target to fly backwards.