I feel like there should be added a new boss troop, available after you defeat all the goblins in the campain: The Goblin Shaman. You already textured him (I'm talking about that fat goblin with a staff fancy clothes).
He would mainly be a back row support, rather than a straight up fighter like the Barbarian King or The Archer Queen.
He should be able to randomly shoot out spells (like the ones in the spell factory), but with on a smaller radius and wouldn't be as strong either, and the more you upgrade him, the stronger his spells get. Special attack: Dizzy all enemy clan castle troops so they can be killed with ease. The Shaman shouldn't have too much health, he would be more of a "Healer" like troop, but, of course, like all the other heroes, he wouldn't die.
Uses: The Shaman can be used for a cheaper way to enhance your troops, at the cost of low health.
To defend against him: You must make sure you can attack the Shaman from multiple sides, so he dies easily(Attacker). You must have really strong defenses against all potions (which you should know a little bit from your previous battles) and be able to kill quick, so Shaman dies. When the Shaman doesn't have any troops left to help, he should just flee.



