Chamber of Secrets

Chamber of Secrets enters the battlefield tapped unless you control a Death Eater or a Slytherin.
{t}: Add {g}, {b}, or {u} to your mana pool.
At the beginning of your upkeep, if you control 3 or more Death Eaters and/or Slytherins, you may sacrifice those creatures and Chamber of Secrets. If you do, create a 10/10 Green Basilisk creature token with First Strike, Deathtouch, and Indestructible.