Clockwork Alicorn

Clockwork Alicorn has flying as long as it has a
+1/+1 counter on it.
At end of combat, if Clockwork Alicorn attacked
or blocked this combat, remove a +1/+1 counter
from it.
{x}{x}: Put X +1/+1 counters on Clockwork
Alicorn. Tap it. Activate this ability only any
time you could cast a sorcery.