I hope it doesn't sound too condescending but it's relatively simple to take take the weapons found in WoW and use the OGL magical weapons and items as a template.
For example, if I was to run an adventure set in Blackrock Depths and the party killed Dagran, I might drop Ironfoe. I'd probably use the Dwarven Thrower as a template (also in the OGL);
- Dwarven Thrower
Weapon (warhammer), very rare (requires attunement by a dwarf)
You gain a +3 bonus to attack and damage rolls made with this magic weapon. It has the thrown property with a normal range of 20 feet and a long range of 60 feet. When you hit with a ranged attack using this weapon, it deals an extra 1d8 damage or, if the target is a giant, 2d8 damage. Immediately after the attack, the weapon flies back to your hand.
Versatile . . . . . . . . . . . . Warhammer
4 - 11, or 4 - 13 Damage
(1d8 or 1d10 + 3 bludgeoning damage)
Requires 2 - 4 Hours for Attunement
(no requirement for Dwarves)
Equip: Can be used as a thrown weapon
(range 20/60), dealing 1d8 damage to
target, 2d8 if target is a Giant.
Chance on Use: 1d6 chance to perform
an extra attack against a target in
melee or thrown range
"Now prepare to meet your doom at the hands of
Ragnaros' most powerful servant!"
I made it 'Chance on use' so you can try again even if you miss.