Maruyama Pond Slime simulate the growth of the multiple organisms. Every organism starts with two adjacent cells. The cells never die. If there are cells available, the last generation of cells (the cells in the extremities) grow following these rules:
1. If there are less than three cells of this organism at the line defined by the end and penultimate cell
a. If the straight line is not blocked, grow straight.
b. If the straight line is blocked and the blocking cell is part of the same organism, make a left turn.
c. If the straight line is blocked and the blocking cell is part of other organisms, make a right turn.
2. If there are more or equal four cells of this organism at the line defined by the end and penultimate cell, the preferred direction is a left turn, then a right turn.