Hydra dark troops

I would like to see a hydra dark troop. That gets increased damage as it gets hurt. Perhaps you could have additional heads pop up while being damaged for a fun factor. Perhaps start off at say 50 damage and increase of damage of 10 points per 75 hit points dropped. Perhaps taking up 10 to 12 spaces for troop capacity. A 150 dark elixir purchase price. with an 350 hit point life total.

I feel like balancing something like this would be tricky