Burst of Rats

Each upkeep create a number of 1/1 rats with Deathtouch equal to the number non-token rats you control.
{t}: Create a 1/1 rat with Deathtouch.
{t}, Sacrifice a rat: Create three 1/1 rats with Deathtouch.
{t}{1}{b}: Put a +1/+1 counter on each rat you control.