Submerged Serpenhydra

Submerged Serpenhydra enters the battlefield with 10 -1/-1 counters on it
When Submerged Serpenhydra enters the battlefield remove X -1/-1 counters from it
{9}{g}{g/u}{u}: Replace all -1/-1 counters on Submerged Serpenhydra with +1/+1 counters