Front Yard, Night

Front Yard, Night enters the battlefield tapped.
{t}: add one {b} for each zombie you control
{3}{b}: create a 2/2 black zombie creature token
{5}{b}{t}: Create a grave ( it is an artifact token with: {3}{t}: Sacrifice this artifact, add one {b} for each
zombie you control, and create a 2/2 black zombie creature token.)