Fire Enchanted

Diablo II	Notation	Basic	Class	Skill	Item	Ally	Quest	Area	Monster	Tale

Fire Resist +75% is applied to Unique when this does not result in a third immunity or increase one of two or more existing immunities. [1]

Monster	Stat	Normal	Nightmare	Hell
Unique	Min Fire Damage	[MonLvl*066/100]	[MonLvl*066/100]	[MonLvl*066/100]
Unique	Max Fire Damage	[MonLvl*100/100]	[MonLvl*100/100]	[MonLvl*100/100]
Minion	Min Fire Damage	0	[MonLvl*033/100]	[MonLvl*033/100]
Minion	Max Fire Damage	0	[MonLvl*050/100]	[MonLvl*050/100]

Bonus damage
Fire damage does not increase with player count, but a critical hit will double it. [4]
Upon death the Unique explodes, applying physical and fire damage based on a percentage of the maximum life of a normal monster of the Unique level:

Stat	Normal	Nightmare	Hell
Fire Damage	5.625-09.375%	3.500-05.833%	0.375-00.625%
Physical Damage	5.625-09.375%	3.500-05.833%	0.375-00.625%
Total Damage	11.250-18.750%	7.000-11.660%	0.750-01.250%
Radius (Yards)	2 2/3	3 1/3	4 0/3

Explosion only applies to players, not mercenary or pets.
Explosion damage can be blocked, and Avoid, Evade and Weapon Block apply.
Explosion damage does not increase with player count, but a critical hit will double it. [8]
+% Damage does not apply to explosion damage. [9]
When a Unique is Fire and Cold Enchanted, two novae and two explosions will be released upon death, although the second of each will be invisible. [10] [11] However, since coldunique missiles have 3 frame next delay, only one will apply its cold damage and length. [12]
When a Unique is Fire and Lightning Enchanted, an invisible explosion will be released whenever it is put into hit recovery. [13] [14] Fixed in D2R. [15]
Fire Enchanted Scarab Demon and its minions will release an invisible explosion whenever put into hit recovery. [16] [17]
Fire and Lightning Enchanted Scarab Demon will release two invisible explosions whenever it is put into hit recovery. [18] [19]

Reference