I'm a bit nervous to post this, So I hope it doesn't get ripped to shreds.
I love Dracoliches, So I made a custom, Near godlike dragon of something resembling a dracolich. As the Field Guide's death dragon was really cool, I just wanted something bigger.
I made this as an end boss for a campaign I'm running.
Drax'xion, The First Death Dragon
Armor Class:28
Hit Dice: 19** (AB +12)
No. of Attacks: 2 claws + paralysis/1 bite or breath/1 tail
Damage: 2d10 claws, 6d8 bite or breath, 2d10 tail
Movement: 30' Fly 80'
No. Appearing: 1
Save As: Magic-User: 19
Morale: 12
Treasure Type: H,A,G(x2)
XP: 5,500
Drax'xion is the undead dread dragon. A former consort to an evil goddess, he was cast out to die, but achieved Undeath by another, mysterious deity. He lies in wait, in a state of lichdom, hidden away inside his cursed lair for the time to avenge his death and rebirth. His influence is small, almost to a point of few knowing of him let alone his true terrifying might. Any adventurer should be wary to seek out this horror!
Drax'xion has three breath weapons and various spell like abilities.
He has a flame breath (Cone) 110' long and 60' wide & a death cloud of the same size dealing 3d10 damage and a save vs Death Ray or contract Mummy Rot, a disease that prevents normal or magical healing. A cure disease spell must be applied to the victim before he or she may again regain hit points.
His third breath weapon is the dreaded Death Wind. A breath 60' long and 30' wide with a save vs Dragon breath or Die! Drax'xion only uses this when he feels he has no choice, as he can only summon the negative energy to do it every few months. As an added effect, any slain undead near the dragon will arise back to undeath to serve him as though they had never taken damage.
Edged weapons deal only half damage to Drax'xion and clerics cannot turn the undead dragon.
Drax'xion Can summon 3 Haunted Bones (Field Guide Page 68) each turn. There can be no more than 6 Haunted Bones summoned by Dragotha at any one time.
Drax'xion can cast:
Death Spell twice per day.
Disintegrate twice per day.
Regenerate three times per day.
Ice Storm twice per day.
Phantasmal Force three times per day.
In addition to his treasure hoard, Drax'xion holds within his lair:
50,000 gp worth of rare gems, 10,000 gp worth of ancient paintings and portraits, 5,000 gp in rare books and tomes, a spellbook with 12,000gp worth of spells inscribed in it, a +5 shortsword of ice, a +4 Mace of fire, a dagger of wishes, and a ring of invisibility.
Merely destroying Drax'xion's body will not kill him, an adventurer needs to find his phylactery and destroy it, else he rise again! It appears as an ornate crystal jar wrapped in dragons teeth, hidden in his hoard. A disintegrate spell, or a wish will destroy it outright. Otherwise the phylactery has 50 hit points and an AC of 20.
If an adventurer were to take the phylactery, Drax'xion will hunt them down to retrieve it. The dragon is able to locate the phylactery from anywhere, at any time regardless of distance.

Never stop dreaming, the imagination is the greatest gift we have.