The horse will cost 80 dark elixir at lvl 1
The main aspect of the horse is that it can hold the troops inside of it
The horse will remain unhostile to the enemy defenses until it starts attacking
Then when it is destroyed hay-presto the troops inside explode from the beasts belly and continue the fight.
At lvl 1 it has 550 hitpoints and 120 attack, the attacking animation will be a battering ram.
Also at lvl 1 it can hold 25 troops until it is upgraded.