Serrated Arrows enters with three arrowhead counters on it. At the beginning of your upkeep, if there are no arrowhead counters on Serrated Arrows, sacrifice it. {T}, Remove an arrowhead counter from Serrated Arrows: Put a -1/-1 counter on target creature.
As Sewer Nemesis enters, choose a player. Sewer Nemesis's power and toughness are each equal to the number of cards in the chosen player's graveyard. Whenever the chosen player casts a spell, that player mills a card.
When Shambling Goblin dies, target creature an opponent controls gets -1/-1 until end of turn.
"The Kolaghan send them at us. We kill and raise them. They fight the next wave the Kolaghan send. It's a neat little cycle." —Asmala, Silumgar sorcerer