Stormfly, Deadly Nadder

Flying, double strike, haste

Stormfly enters with five spine counters.
{t}: Put X spine counters on Stormfly where X is the number of Dragons you control.
{t}, Remove any number of spine counters from Stormfly. Stormfly deals X damage to target permanent or player where X is the number of spine counters removed from Stormfly.

Rider's Mount (You can have two commanders if the other is a Dragon Rider.)