Frost Dragon/1.03

Frost Dragons are elite flyers. Frost Dragons may be the physically weakest of all Dragons, but their ability to consistently freeze targets, as well as having a rarely resisted attack type, makes them one of the best Dragons around! Whether you use them to hinder your enemies to allow your other units / towers to exploit the speed drops or use them as outright attackers, they surely wont disappoint - even in the face of a Titan! You can even recruit one for your Hero's retinue from the official campaign.

Dark Dwarves
Pretty much everything in the Dark Dwarven army is slow or / and has a slow attack speed. However, the Frost Dragon's trait of freezing the enemy can bring the combat down to a more even pace, where your Dark Dwarven units no longer seem so slow. This can massively help your siege weapons fire off their attacks against the enemy before they can react or destroy them in time. The Frost Dragon is no slouch when it comes to raw power, either, as frost type attacks are rarely resisted and a large 40 damage of it is sure to dent anything not immediately killed outright by the attack. Although, with the sheer power of the Dark Dwarven siege weapons and the Frost Dragon's lower than average HP (for a Dragon), it's best to limit the Frost Dragon to a support role and take out or hinder anything that threatens your vulnerable constructs.

Benefits from Armorer and Mithril researches.

Empire
The Frost Dragon also hits the same resource problem as the Swamp Dragon, but due to its cold attack and effects that come with it, the Frost Dragon serves a unique roll for the Empire and makes the Dragon an unit that deserves to be produced. Its cold attack alone gives the Empire an ultimate counter to the dreaded Daemon, an unit that would have caused many problems for the Empire throughout the game, and its ability to slow down enemies literally stops the tougher enemies in their tracks.

Although its production cost causes issues along side mass-Mage production, one should not discount the Frost Dragon because of it and should consider producing one sooner than later. If playing against Daemons or an enemy with a lot of tough, hard-hitting units, then the Frost Dragon should take priority. The Income and Trade skills researched early game should help make producing a Frost Dragon easier.

Also, do not forget that the Empire have access to Mages that can heal (White Mage). When your Dragons are low on HP, pull them back to base and get your White Mages to heal them. This allows the Empire's Dragons to stick around longer than other races' Dragons and thus help keep production costs of them down to a minimum.

Benefits from Armorer research.

High Elves
Frost Dragons are a great Dragon choice, but the High Elves aren't strangers to frost attacks. Both of their spellcasters have frost attacks and spells, one of which is the Freeze spell that has the same effects as the Frost Dragon's breath attack, but with the added effect of being issued across a large radius. This makes the Frost Dragon's unique roll a lot less unique for the High Elves. Considering their other Dragon choice as well, and it's no mystery why the High Elves common Dragon choice is the Celestial variant. That's not to say the Frost Dragon has no place in the High Elven army, their natural bulk and the absents of mana for their freezing allows them to function on the front line and assail even Mana-Drain units and still remain effective.

Minotaurs
The combination of Frost Dragons and Minotaur Kings will destroy absolutely any unit and with ease. Titans, Dragons and even enemy Heroes will simply fall, for a sheer drop in attack speed means even the hardest hitters around wont be able to rid you of your attack combination in time, while it, in turn, it lays to waste to what ever your enemy can throw at you. But really, the ability to greatly reduce the enemy units' attack speed can make a Minotaur invasion all but unstoppable - as their high power would normally quickly dispose of most threats and the Frost Dragons aid ensures that nothing will fight back in time before their ultimate demise, leaving your units still fresh for another confrontation. However, Frost Dragons have little effect against towers, though, but the Minotaurs basic infantry are surprisingly effective for dealing with that task when fully upgraded. But, of course, you always have the option of siege weapons.

Benefits from Training and Eagle Eye researches.