Lung, Draconic Tyrant

{b/r}: Regenerate Lung, Draconic Tyrant.
Whenever Lung, Draconic Tyrant blocks or is blocked, this creature gains X +1/+1 counters
where X is the number of creatures blocking or
being blocked by this creature.
During any end step, if Lung, Draconic Tyrant
hasn't taken damage since your last end step,
remove one +1/+1 counter.
If this creature has no +1/+1 counters, transform
Lung, Draconic Tyrant.