Skullsludge

As an additional cost to cast Skullsludge, exile X creature cards from your graveyard.
Skullsludge enters the battlefield with X +1/+1 counters on it.
{2}{b/g}, Remove a +1/+1 counter from Skullsludge:
If {b} was spent to activate this ability, up to one
target creature gets -2/-2 until end of turn. If {g} was spent to activate this ability, Skullsludge
gains hexproof until end of turn.