The Archer Queen is basically a stronger, more powerful version of the Archer.
She is automatically summoned once the Archer Queen Altar is constructed, which costs 40,000 Dark Elixir.
The Archer Queen is an immortal unit, so she only has to be summoned once. However, if she is injured or ‘falls’ in battle, she must regenerate her health by sleeping for a period of time before she can be used again. If you attack a village while its Archer Queen is still regenerating, the Altar will be empty.
The amount of time she sleeps to regenerate is directly proportional to the health she has left at the end of the battle. So if she is not damaged then she is ready to fight immediately; however, if she falls in battle or even gets hit, then she must sleep for some time to regenerate.
The more the Archer Queen is upgraded, the more time it will take to fully regenerate her health.
You can temporarily quadruple the hero’s healing rate for 1 hour by spending 5 Gems.
As in the January 29th 2014 update, the Archer Queen gained a new special ability: Royal Cloak. The Royal Cloak allows her to become “invisible” to enemy defenses for a short period of time, in addition to greatly increasing her damage, restoring some of her health and summoning up to 12 Archers to aid her in battle (although the Archers are summoned by Royal Cloak, they are otherwise unaffected by it unlike the Barbarian King, where barbarians are affected). The Archer Queen gains this ability at Level 5, and it becomes more powerful every five levels she gains.
Unlike the Barbarian King, the Archer Queen can attack air units like Balloons, Dragons, or Minions, making her effective in guarding a village against players who utilize air raids.